…dling

- Renamed test functions for clarity.
- Introduced DummyModule and DummyLint classes to simulate module and lint behavior.
- Enhanced tests for handling invalid, empty, and missing dependencies in environment.yml files.
- Improved assertions to validate sorting and schema compliance.

- Replaced yaml library with ruamel.yaml for improved YAML processing.
- Added schema validation for environment.yml files.
- Implemented sorting for dependencies and channels, ensuring proper order.
- Updated file writing to include schema lines and sorted content.
- Enhanced logging for sorting actions and validation results.

…processing

- Updated the YAML library from ruamel.yaml to PyYAML for improved compatibility.
- Changed YAML loading to use safe_load for better security.
- Enhanced YAML dumping with specific formatting options for clarity.
- Adjusted error handling to reflect the new library usage.

Did my best, and wanted to keep the code verbatim before things really start shifting.

… version handling

- Introduced separate test files for module changes, deprecations, todos, and version functionalities.
- Implemented basic structure and placeholder tests for each new test file to ensure future functionality can be added.
- Removed the old test_lint.py file to streamline the test organization.

…ssed tests

- Updated the assertion to verify the presence of "test_snap_md5sum" in the passed tests.
- Improved handling to accommodate both LintResult objects and tuple formats for better robustness.

Add new lint check `test_snap_version_content` to ensure version information
in test snapshots contains actual content instead of MD5/SHA hash values.
This addresses the issue where version snapshots were storing hash values
like "versions.yml:md5,949da9c6297b613b50e24c421576f3f1" instead of
actual version content like {"ALE": {"ale": "20180904"}}.

Changes:
- Add version content validation in module_tests.py with regex patterns
- Add comprehensive tests for both invalid (hash) and valid (content) cases
- Add pytest issue marker support for linking tests to GitHub issues
- Update pyproject.toml with new pytest marker configuration

Fixes: nf-core/modules#6505

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>