This ensures we don't attempt adding a locale to a path when the locale is already present but in a different casing, this also ensures we successfully remove the locale if the casing differs in the path. Additional tests have been added in the `i18n-support` suites to ensure this is working correctly.
## Bug
- [x] Related issues linked using `fixes #number`
- [x] Integration tests added
Fixes: https://github.com/vercel/next.js/issues/23553
a153b63240