Include actual media type in InvalidSchemaMediaTypeException

[Copilot]

Fix InvalidSchemaMediaTypeException to include actual media type

• Update the exception message in UriRetriever::confirmMediaType() to include the actual media type discovered
• Add a test to verify the new exception message includes both expected and actual media types
• Add a changelog entry documenting this improvement
• Run existing tests to ensure no regressions
• Request code review
• Run security scan
• Address review feedback - Add PR link to CHANGELOG

Summary

This PR fixes the issue where InvalidSchemaMediaTypeException only reported what media type was expected but not what was actually received.

Changes:

• Updated exception message from "Media type application/schema+json expected" to "Media type application/schema+json expected, but text/html given" (example)
• Added test to verify the new exception message format
• Updated CHANGELOG.md with PR link

Testing:

• All 27 tests in UriRetrieverTest pass
• New test specifically validates the exception message includes the actual media type

Original prompt

---

This section details on the original issue you should resolve

<issue_title>UriRetriever: Report what Media type is</issue_title>
<issue_description>https://github.com/jsonrainbow/json-schema/blob/53725e0/src/JsonSchema/Uri/UriRetriever.php#L94

Seen at https://integration.wikimedia.org/ci/job/quibble-for-mediawiki-core-vendor-mysql-php83/4583/console when trying to upgrade the OpenApi spec we're using in testing (so on 5.3.1, currently) from 3.0.3 to 3.0.4.

https://gerrit.wikimedia.org/r/c/mediawiki/core/+/1229635/1/tests/phpunit/integration/includes/Rest/Handler/data/OpenApi-3.0.json

While it's helpful to be told what media type something isn't... It's not very helpful if you're not also told what media type something apparently is.

18:42:26 There were 6 errors:
18:42:26 
18:42:26 1) RestStructureTest::testModuleDefinitionFiles with data set "/workspace/src/includes/Rest/content.v1.json" (stdClass Object (...))
18:42:26 JsonSchema\Exception\InvalidSchemaMediaTypeException: Media type application/schema+json expected
18:42:26 
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/Uri/UriRetriever.php:92
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/Uri/UriRetriever.php:209
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/Uri/UriRetriever.php:181
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/SchemaStorage.php:52
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/SchemaStorage.php:115
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/SchemaStorage.php:138
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/SchemaStorage.php:162
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/Constraints/Constraint.php:123
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/Constraints/ObjectConstraint.php:145
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/Constraints/ObjectConstraint.php:47
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/Constraints/Constraint.php:90
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/Constraints/UndefinedConstraint.php:74
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/Constraints/UndefinedConstraint.php:52
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/Constraints/Constraint.php:123
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/Constraints/UndefinedConstraint.php:319
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/Constraints/UndefinedConstraint.php:49
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/Constraints/Constraint.php:123
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/Constraints/ObjectConstraint.php:145
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/Constraints/ObjectConstraint.php:47
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/Constraints/Constraint.php:90
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/Constraints/UndefinedConstraint.php:74
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/Constraints/UndefinedConstraint.php:52
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/Constraints/Constraint.php:123
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/Constraints/SchemaConstraint.php:92
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/Validator.php:61
18:42:26 /workspace/src/tests/phpunit/JsonSchemaAssertionTrait.php:70
18:42:26 /workspace/src/tests/phpunit/structure/RestStructureTest.php:361
Logs generated by test
18:42:26 
18:42:26 2) RestStructureTest::testModuleDefinitionFiles with data set "/workspace/src/includes/Rest/site.v1.json" (stdClass Object (...))
18:42:26 JsonSchema\Exception\InvalidSchemaMediaTypeException: Media type application/schema+json expected
18:42:26 
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/Uri/UriRetriever.php:92
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/Uri/UriRetriever.php:209
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/Uri/UriRetriever.php:181
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/SchemaStorage.php:52
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/SchemaStorage.php:115
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/SchemaStorage.php:138
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/SchemaStorage.php:162
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/Constraints/Constraint.php:123
18:42:26 /workspace/src/vendor/justinrainbow/json-schema/src/JsonSchema/Constraints/ObjectConstraint.php:145
18:42:26 /workspace/src/vendor/justinrainbow...

</details>



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- Fixes jsonrainbow/json-schema#871

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