Group CodeQL action updates in Dependabot

[muir]

This PR groups CodeQL action updates in Dependabot to ensure that init/autobuild/analyze steps stay on the same version.

The init, autobuild, and analyze steps must stay on the same version, so they have to be bumped in a single pull request.

This change adds a groups configuration to .github/dependabot.yml that groups all github/codeql-action* updates together.

Related to: singlestore-labs/events#192

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 81.74%. Comparing base (4e9df19) to head (a54286b).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #387   +/-   ##
=======================================
  Coverage   81.74%   81.74%           
=======================================
  Files          16       16           
  Lines        1786     1786           
=======================================
  Hits         1460     1460           
  Misses        200      200           
  Partials      126      126           

Flag	Coverage Δ
go_tests	19.70% <ø> (ø)
mysql_tests	47.91% <ø> (ø)
pg_tests	51.83% <ø> (ø)
singlestore_tests	44.75% <ø> (ø)

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