Restart server on config file change

[edvilme]

This pull request introduces a new mechanism to watch for changes in Flake8 configuration files and automatically trigger the server to rerun when these files are updated, created, or deleted. This ensures that changes to linting configurations are picked up immediately, improving the developer experience.

Configuration file watching improvements:

• Added a new utility function createConfigFileWatchers in configWatcher.ts to watch for changes in Flake8 configuration files (.flake8, setup.cfg, tox.ini). When any of these files are changed, created, or deleted, the server is notified to rerun. [1] [2]
• Integrated the new config file watchers into the extension activation lifecycle by registering them in extension.ts so they are properly disposed of with the extension context. [1] [2]