Add E2E tests for multi-ecosystem group filtering properties

[a-schur]

Tests for update-types, dependency-type, and exclude-patterns support in multi-ecosystem groups to validate the feature implemented in github/dependabot-api#7434.

Fixes: #13572

Test coverage:

• update-types filtering (minor, patch)
• dependency-type filtering (development, production)
• exclude-patterns filtering
• patterns combined with update-types
• multi-directory scenarios
• combined filter scenarios

What are you trying to accomplish?

Anything you want to highlight for special attention from reviewers?

How will you know you've accomplished your goal?

Checklist

• I have run the complete test suite to ensure all tests and linters pass.
• I have thoroughly tested my code changes to ensure they work as expected, including adding additional tests for new functionality.
• I have written clear and descriptive commit messages.
• I have provided a detailed description of the changes in the pull request, including the problem it addresses, how it fixes the problem, and any relevant details about the implementation.
• I have ensured that the code is well-documented and easy to understand.

[Copilot]

Pull request overview

This PR adds comprehensive end-to-end test coverage for multi-ecosystem grouped dependency updates, testing the filtering properties (update-types, dependency-type, and exclude-patterns) that were implemented in github/dependabot-api#7434. These tests validate that the multi-ecosystem update feature correctly applies various filters when grouping dependencies across different scenarios.

Key changes:

• Six new test files covering different filtering scenarios in multi-ecosystem grouped updates
• Tests verify update-types filtering, dependency-type filtering, exclude-patterns, and combinations thereof
• Includes tests for both single and multi-directory scenarios

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
silent/tests/testdata/vu-multi-ecosystem-update-types.txt	Tests update-types filtering (minor and patch) in multi-ecosystem groups
silent/tests/testdata/vu-multi-ecosystem-patterns-with-filters.txt	Tests combining pattern matching with update-types filters
silent/tests/testdata/vu-multi-ecosystem-multidir-update-types.txt	Tests update-types filtering across multiple directories
silent/tests/testdata/vu-multi-ecosystem-exclude-patterns.txt	Tests exclude-patterns filtering in multi-ecosystem groups
silent/tests/testdata/vu-multi-ecosystem-dependency-type.txt	Tests dependency-type filtering (development vs production)
silent/tests/testdata/vu-multi-ecosystem-combined-filters.txt	Tests combining multiple filter types (dependency-type, update-types, exclude-patterns)

[rickreyhsig]

Would major always be excluded?

[a-schur]

If the update-types list only includes minor and patch, then major updates are excluded for that group. Only dependencies that qualify for minor or patch updates are handled; major updates will be ignored for this config.