gh-157581: Handle exceptions in can_colorize

Handle unexpected exceptions in can_colorize instead of surfacing them
in the REPL

Author: edvilme

Lib/_colorize.py

@@ -603,6 +603,8 @@ def _safe_getenv(k: str, fallback: str | None = None) -> str | None:
         return os.isatty(file.fileno())
     except OSError:
         return hasattr(file, "isatty") and file.isatty()
+    except Exception:
+        return False
 
 
 default_theme = Theme()