Add flag to re-write sidebar.js (and other auto-generated files)

Is your feature request related to a problem?

Similar to https://github.com/PaloAltoNetworks/docusaurus-openapi-docs/issues/615#issuecomment-2197534877, I noticed that changes to the OpenAPI specs aren't reflected in sidebar.ts file: https://github.com/PaloAltoNetworks/docusaurus-openapi-docs/blob/00631740bd7a06d447ed7eb2aa4b7b7259593e71/packages/docusaurus-plugin-openapi-docs/src/index.ts#L181-L194

I think it would be nice to add an --overwrite arg in CLI that would allow you to overwrite this!

Describe the solution you'd like

Something similar to docusaurus gen-api-docs <plugin_id> --overwrite

Describe alternatives you've considered

Not blocked, able to just clean/delete the repo but it would be a nice step to include. It wasn't super obvious to me when I first did this and spend some time trying to debug why my updates weren't appearing in my docs.

Perhaps also maybe in output text say "warning: OpenAPI spec differs from data currently saved in <destination_path>.sidebar.ts file. If you would like to update this file, please re-run with the --overwrite flag: docusaurus gen-api-docs <plugin_id> --overwrite"

Additional context

Start in packages/docusaurus-plugin-openapi-docs/src/index.ts around lines 181-194, where generated sidebar.ts output is handled, and trace the docusaurus gen-api-docs CLI arguments. Add the requested --overwrite behavior and warning for differing generated files; done means updated OpenAPI specs can regenerate sidebar.ts and other auto-generated files without manually deleting them.