Bump sqlfluff from 1.4.5 to 3.0.2 in /src

Bumps [sqlfluff](https://github.com/sqlfluff/sqlfluff) from 1.4.5 to 3.0.2.
- [Release notes](https://github.com/sqlfluff/sqlfluff/releases)
- [Changelog](https://github.com/sqlfluff/sqlfluff/blob/main/CHANGELOG.md)
- [Commits](sqlfluff/sqlfluff@1.4.5...3.0.2)

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

Signed-off-by: dependabot[bot] <[email protected]>

src/requirements.txt

@@ -4,4 +4,4 @@ gunicorn==21.2.0
 pytest==8.1.1
 pytest-watch==4.2.0
 pytest-cov==4.1.0
-sqlfluff==1.4.5
+sqlfluff==3.0.2