Bump sqlfluff from 3.4.1 to 3.4.2 in /src (#4164)

Bumps [sqlfluff](https://github.com/sqlfluff/sqlfluff) from 3.4.1 to 3.4.2.
- [Release notes](https://github.com/sqlfluff/sqlfluff/releases)
- [Changelog](https://github.com/sqlfluff/sqlfluff/blob/main/CHANGELOG.md)
- [Commits](sqlfluff/sqlfluff@3.4.1...3.4.2)

---
updated-dependencies:
- dependency-name: sqlfluff
  dependency-version: 3.4.2
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

src/requirements.txt

@@ -4,7 +4,7 @@ gunicorn==23.0.0
 pytest==8.4.1
 pytest-watch==4.2.0
 pytest-cov==6.2.1
-sqlfluff==3.4.1
+sqlfluff==3.4.2
 
 # sql/util/* dependencies
 pandas==2.3.1