Fix GitIgnorePatternError

✅ Solution

GitIgnorePatternError usually arises from invalid patterns in your `.gitignore` file, particularly those incompatible with the pathspec library used by Black. Resolve this by carefully reviewing your `.gitignore` file, correcting or removing any malformed patterns like those with unescaped special characters or syntax errors, and then retry running Black. Using online `.gitignore` validators can help identify problematic entries.