GRM-24: fix: resolve bandit security warnings in source code and tests

scripts/validate_commit_msg.py

@@ -8,7 +8,7 @@ Rules:
 """
 
 import re
-import subprocess
+import subprocess  # nosec B404
 
 import click
 
@@ -24,7 +24,7 @@ def first_line(text: str) -> str:
 
 def get_branch() -> str:
     try:
-        result = subprocess.run(
+        result = subprocess.run(  # nosec
             ["git", "symbolic-ref", "--short", "HEAD"],
             capture_output=True,
             text=True,