Add parser support for dbt.config.meta_get() in Python models

[venkaa28]

Resolves #

Updates the Python model parser to recognize and track dbt.config.meta_get() calls, extracting keys and default values for runtime use.

Note: Python models only support meta_get(), not meta_require() (unlike SQL models which have both).

What Changed

• Parser Updates: Modified models.py to recognize dbt.meta_get() function calls
• Key Tracking: Extracts meta keys and default values from meta_get() calls
• Validation: Validates argument count (1-2 args required)
• Context Passing: Passes meta_keys_used and meta_keys_defaults to runtime macro
• Tests: Added 6 unit tests covering various meta_get scenarios

Backwards Compatibility

• Fully backwards compatible - parser only tracks new function, doesn't break existing code
• Old pattern (dbt.config.get('meta_key')) continues to be parsed (though it won't work at runtime)

Related PRs

• dbt-adapters PR: Runtime macro that uses parsed meta keys
• Fusion PR: Deprecation warnings for old pattern
• dbt-autofix PR: Automatic migration tool

Checklist

• I have read the contributing guide and understand what's expected of me.
• I have run this code in development, and it appears to resolve the stated issue.
• This PR includes tests, or tests are not required or relevant for this PR.
• This PR has no interface changes (e.g., macros, CLI, logs, JSON artifacts, config files, adapter interface, etc.) or this PR has already received feedback and approval from Product or DX.
• This PR includes type annotations for new and modified functions.

[github-actions]

Thank you for your pull request! We could not find a changelog entry for this change. For details on how to document a change, see the contributing guide.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.36%. Comparing base (7b9d75b) to head (6adce16).
⚠️ Report is 9 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #12453      +/-   ##
==========================================
- Coverage   91.39%   91.36%   -0.04%     
==========================================
  Files         203      203              
  Lines       25405    25428      +23     
==========================================
+ Hits        23220    23232      +12     
- Misses       2185     2196      +11     

Flag	Coverage Δ
integration	88.20% <37.50%> (-0.12%)	⬇️
unit	65.09% <100.00%> (+0.03%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Components	Coverage Δ
Unit Tests	65.09% <100.00%> (+0.03%)	⬆️
Integration Tests	88.20% <37.50%> (-0.12%)	⬇️

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.