PYTHON-5853 Dependabot improvements

[blink1073]

PYTHON-5853

Changes in this PR

• Replaced the pip Dependabot ecosystem entry with uv, since GitHub Dependabot now has native uv support.
• Added cooldown: default-days: 7 to the uv ecosystem entry (matching the existing github-actions entry).
• Bumped check-jsonschema pre-commit hook from 0.29.0 to 0.37.2 to pick up the updated SchemaStore Dependabot schema that recognises uv as a valid ecosystem.

Test Plan

The pre-commit check-dependabot hook validates the updated config and passes with check-jsonschema 0.37.2.

Checklist

Checklist for Author

• Did you update the changelog (if necessary)?
• Is there test coverage?
• Is any followup work tracked in a JIRA ticket? If so, add link(s).

Checklist for Reviewer

• Does the title of the PR reference a JIRA Ticket?
• Do you fully understand the implementation? (Would you be comfortable explaining how this code works to someone else?)
• Is all relevant documentation (README or docstring) updated?

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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