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: https://github.com/dependabot/dependabot-core/issues/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

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Checklist

• [x] I have run the complete test suite to ensure all tests and linters pass.
• [x] I have thoroughly tested my code changes to ensure they work as expected, including adding additional tests for new functionality.
• [x] I have written clear and descriptive commit messages.
• [x] 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.
• [x] I have ensured that the code is well-documented and easy to understand.