Fix Python SyntaxWarning in database migration regex

Use raw string (r"") for SQL containing regex pattern to avoid
Python SyntaxWarning about invalid escape sequence '\.'

CHANGELOG.md

@@ -84,6 +84,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fixed deploy jobs running when secrets scan fails (added `secrets` to deploy dependencies)
 - Fixed dev environment memory requests to equal limits per cluster Kyverno policy
 - Fixed init containers missing resource limits (Kyverno policy compliance)
+- Fixed Python SyntaxWarning for invalid escape sequence in database migration regex pattern
 
 ### Removed
 - Removed unused `store_streaming()` method from storage.py (#51)

backend/app/database.py

@@ -210,7 +210,7 @@ def _run_migrations():
         END $$;
         """,
         # Migrate existing semver tags to package_versions
-        """
+        r"""
         DO $$
         BEGIN
             IF EXISTS (SELECT 1 FROM information_schema.tables WHERE table_name = 'package_versions') THEN