Refresh project dependency handling

[asnare]

This PR updates the project dependency and CI handling:

• Developer and CI/CD workflows now use frozen-mode for uv operations.
• Linting is implemented for the lockfiles.
• Explicit dependencies are updated: pip, pytest, mypy and databricks-labs-pylint.
• Various transitive dependencies are also updated because we now lock to the highest version allowed instead of the lowest.
• The CI/CD environments are now marked as being unrelated to deployments.

Subsumes:

• Bump databricks-labs-pylint from 0.3.0 to 0.5.0 #381
• Bump mypy from 1.19.1 to 1.20.2 #382
• Bump types-pyyaml from 6.0.12.20250915 to 6.0.12.20260408 #383
• Bump pytest from 9.0.2 to 9.0.3 #384
• Bump pip from 26.0.1 to 26.1 #385

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 80.15%. Comparing base (906d6fc) to head (f4b64b0).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #386   +/-   ##
=======================================
  Coverage   80.15%   80.15%           
=======================================
  Files          17       17           
  Lines        2474     2474           
  Branches      403      403           
=======================================
  Hits         1983     1983           
  Misses        364      364           
  Partials      127      127           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

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

[github-actions]

✅ 40/40 passed, 2 skipped, 1m59s total

_{Running from acceptance #443}

[dgomez04]

LGTM