Fix code formatting and linting issues

- Updated GitHub Actions workflow to use correct flake8 configuration
- Fixed line length issues by using 88 characters as configured
- Removed unused imports and trailing whitespace
- Fixed f-string placeholders and unused variables
- All linting checks now pass with project configuration

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

wikijs/version.py

@@ -4,4 +4,4 @@ __version__ = "0.1.0"
 __version_info__ = (0, 1, 0)
 
 # Version history
-# 0.1.0 - MVP Release: Basic Wiki.js integration with Pages API
+# 0.1.0 - MVP Release: Basic Wiki.js integration with Pages API