Fix https://github.com/microsoft/vcpkg/issues/38588
Include the GL extension in the header file by adding the parameter
`--ext`.
Note: This method only adds GL extension and does not delete any
original method implementation.
Upstream：
```
The generator script optionally takes the arguments:
--ext to include the GL Extensions in output header.
```
https://github.com/skaslev/gl3w?tab=readme-ov-file#options
- [x] Changes comply with the [maintainer
guide](https://github.com/microsoft/vcpkg-docs/blob/main/vcpkg/contributing/maintainer-guide.md).
- [ ] ~~SHA512s are updated for each updated download.~~
- [ ] ~~The "supports" clause reflects platforms that may be fixed by
this new version.~~
- [ ] ~~Any fixed [CI
baseline](https://github.com/microsoft/vcpkg/blob/master/scripts/ci.baseline.txt)
entries are removed from that file.~~
- [ ] ~~Any patches that are no longer applied are deleted from the
port's directory.~~
- [x] The version database is fixed by rerunning `./vcpkg x-add-version
--all` and committing the result.
- [x] Only one version is added to each modified port's versions file.
* [gl3w] use khrplatform.h from the egl-registry port
The file was changed yesterday, invalidating the hash: KhronosGroup/EGL-Registry@57b4876de0.
* [gl3w] migrate to new functions from vcpkg-cmake{,-config}
* [gl3w] bump port version
