Address code review feedback - improve error handling and use bash built-ins

Co-authored-by: jmiller-moko <230051081+jmiller-moko@users.noreply.github.com>

scripts/run/check_version.sh

@@ -85,7 +85,7 @@ validate_prefix() {
 
 validate_version() {
   local v="$1"
-  if ! printf '%s' "$v" | grep -Eq '^[0-9]{2}\.[0-9]{2}\.[0-9]{2}$'; then
+  if [[ ! "$v" =~ ^[0-9]{2}\.[0-9]{2}\.[0-9]{2}$ ]]; then
     die "Invalid version format: $v (expected NN.NN.NN)"
   fi
 }

scripts/validate/workflows.sh

@@ -52,7 +52,12 @@ validate_yaml_syntax() {
   
   python3 - "$file" <<'PYEOF'
 import sys
-import yaml
+
+try:
+    import yaml
+except ModuleNotFoundError:
+    print("WARNING: PyYAML module not installed. Install with: pip3 install pyyaml")
+    sys.exit(0)
 
 file_path = sys.argv[1]