chore: update .gitignore to exclude testing folder

Added testing/ folder to .gitignore for local manual testing scripts
that should not be committed to the repository.

Author: smypmsa

.gitignore

@@ -620,6 +620,7 @@ healthchecksdb
 MigrationBackup/
 
 testing.py
+testing/
 
 # End of https://www.gitignore.io/api/osx,python,pycharm,windows,visualstudio,visualstudiocode
 examples/config.json