fix(docker): add user creation and permissions in Dockerfile (#442)

Co-authored-by: Copilot <copilot@github.com>
Reviewed-on: #442

tests/test_datetime.py

@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 """Provides test cases for app/utils/datetime.py."""
 
 import pytest