feat: removing unused variable (#815)

### Feature or Bugfix
- Feature

### Detail
- Removing unused variable in local graphql server pointing to a fixed
AWS region

### Relates
N/A

### Security
N/A


By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache 2.0 license.

Co-authored-by: Zilvinas Saltys <zilvinas.saltys@yahooinc.com>

backend/local_graphql_server.py

@@ -24,7 +24,6 @@
 logger.propagate = False
 logger.setLevel(logging.INFO)
 
-sts = boto3.client('sts', region_name='eu-west-1')
 Worker.queue = Worker.process
 ENVNAME = os.getenv('envname', 'local')
 logger.warning(f'Connecting to database `{ENVNAME}`')