`OBJECT` libraries have historically exhibited poor support for various
features, both in the past and now. For example, see one of the latest
issues:
- https://gitlab.kitware.com/cmake/cmake/-/issues/24058
Furthermore, CMake maintainers have acknowledged:
> In general, however, where there is a choice, static libraries will
> typically be the more convenient choice in CMake projects.
This change:
1. Converts the `bitcoin_clientversion` library from an `OBJECT` library
to a `STATIC` library.
2. Removes an obsolete workaround.
3fd64efb43