There is something you seem failing to grasp.
This issue appears, if as supposed, because a framework library has been updated. In such a case, packages in repositories are rebuilt by the package maintainers in order to be compatible with it.
But this is an AUR package, so it doesn’t follow the same rules:
The package – actually the PKGBUILD – is updated only if the application itself is updated. Since here it is its framework dependency that is updated, and that the application actually works with both versions, the PKGBUILD does not need to be updated.
Nonetheless, the package needs to be rebuilt in order to use the new version of the framework, hence the suggested solution.
Lastly, changing mirrors won’t do anything, as this is an AUR package, and AUR isn’t mirrored.
You can still wait for its next update if you prefer. I’d advise against this as it may not happen as soon as you think…