Update tools/chelon-sign

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: atomicturtle

tools/chelon-sign

@@ -44,6 +44,7 @@ def get_gpg_version() -> str:
         if 'gpg (GnuPG)' in first_line:
             return first_line.split()[-1]
     except (subprocess.CalledProcessError, FileNotFoundError, IndexError):
+        # If gpg is missing or its output is unexpected, fall back to a default version string.
         pass
     return "2.4.4"