Broken (unnecessarily munged) repo hyperlinks in library reference pages

### Describe the problem

After adding some of my libraries to the library registry, I note that the automatically-generated library pages (example: https://docs.arduino.cc/libraries/keyhole/ ) are taking the repo URLs I supplied (in that case: https://bitbucket.org/jezhill/Keyhole ) and automatically appending `.git` to them. This leads to a potentially-invalid hyperlink.

### To reproduce

- Go to the page https://docs.arduino.cc/libraries/keyhole
- Hover over the link that says GO TO REPOSITORY.
- Note that it leads to https://bitbucket.org/jezhill/Keyhole.git
- Note that this is different from the actual library-registry entry, which is https://bitbucket.org/jezhill/Keyhole
- Click on the link.
- Note that the bitbucket webserver chokes on the modified URL (we get to a page that spins its progress-wheel indefinitely, waiting for the content to be populated).
- Try the same thing with any other arduino library whose source repo is hosted on bitbucket.

### Expected behavior

Expected behavior is to see bitbucket's web-interface version of the repo. This happens correctly if you point your browser to the original URL listed in https://github.com/arduino/library-registry/blob/main/repositories.txt (i.e. https://bitbucket.org/jezhill/Keyhole without the `.git` suffix)

### Additional context

Of course you could (rightly) argue that this *particular* problem is a bitbucket.org server issue rather than an arduino.cc issue. But (leaving aside the fact that, as a non-paying user of bitbucket, I'm not going to get the attention of their support or webmaster) the general principle remains that it's probably wiser to just _not_ automatically change the provided URL on the arduino.cc side, to avoid any such unforeseen weirdness.

Note that, as an argument to `git clone` the URL works fine both with _and_ without the suffix. This particular problem only occurs with the web interface. In any case, I don't see any advantage in adding the `.git` suffix, especially to a hyperlink that is designed for human clicking.

### Issue checklist

- [x] I searched for previous reports in [the issue tracker](https://github.com/arduino/library-registry/issues?q=)
- [x] My report contains all necessary details

Start by comparing the repository URL in repositories.txt with the URL rendered by the library reference page at docs.arduino.cc/libraries/keyhole. Trace where the generated GO TO REPOSITORY link appends .git; done means preserving the supplied URL so Bitbucket repository links open in the web interface.

Written by the indexing model from the issue text.