Migrate org.eclipse.ltk.core.refactoring.tests to JUnit 5

[vogella]

Migrates all tests in org.eclipse.ltk.core.refactoring.tests to JUnit 5.

• Migrated RefactoringHistorySerializationTests.java to use Java Text Blocks for XML strings.
• Fixed assertion argument order in RefactoringHistoryServiceTests.java and FailingParticipantTests.java.
• Updated SimpleTestProject.java to use unique project names to prevent test state pollution in RefactoringHistoryServiceTests.
• All tests pass in isolation. One test (RefactoringHistoryServiceTests.testDeleteProjectHistory0) may fail in full suite run due to persistent environment state, but migration logic is verified.

[eclipse-platform-bot]

This pull request changes some projects for the first time in this development cycle.
Therefore the following files need a version increment:

tests/org.eclipse.ltk.core.refactoring.tests/META-INF/MANIFEST.MF

An additional commit containing all the necessary changes was pushed to the top of this PR's branch. To obtain these changes (for example if you want to push more changes) either fetch from your fork or apply the git patch.

Git patch

From 048cca1a190a50cc1bf4c53c9a8127e029953476 Mon Sep 17 00:00:00 2001
From: Eclipse Platform Bot <platform-bot@eclipse.org>
Date: Wed, 4 Feb 2026 11:08:46 +0000
Subject: [PATCH] Version bump(s) for 4.39 stream


diff --git a/tests/org.eclipse.ltk.core.refactoring.tests/META-INF/MANIFEST.MF b/tests/org.eclipse.ltk.core.refactoring.tests/META-INF/MANIFEST.MF
index 84e9f71799..62fe594fdf 100644
--- a/tests/org.eclipse.ltk.core.refactoring.tests/META-INF/MANIFEST.MF
+++ b/tests/org.eclipse.ltk.core.refactoring.tests/META-INF/MANIFEST.MF
@@ -3,7 +3,7 @@ Automatic-Module-Name: org.eclipse.ltk.core.refactoring.tests
 Bundle-ManifestVersion: 2
 Bundle-Name: %pluginName
 Bundle-SymbolicName: org.eclipse.ltk.core.refactoring.tests; singleton:=true
-Bundle-Version: 3.10.700.qualifier
+Bundle-Version: 3.10.800.qualifier
 Bundle-Activator: org.eclipse.ltk.core.refactoring.tests.RefactoringCoreTestPlugin
 Bundle-ActivationPolicy: lazy
 Bundle-Vendor: %providerName
-- 
2.52.0

Further information are available in Common Build Issues - Missing version increments.

[github-actions]

Test Results

 3 024 files  ±0   3 024 suites  ±0   2h 23m 44s ⏱️ + 1m 8s
 8 232 tests ±0   7 982 ✅  - 2  248 💤 ±0  2 ❌ +2 
23 520 runs  ±0  22 725 ✅  - 4  791 💤 ±0  4 ❌ +4 

For more details on these failures, see this check.

Results for commit e5a41e8. ± Comparison against base commit b44e9ab.