fix siplib build on Windows

[DietmarSchwertberger]

When trying to build 4.2.2 with Python 3.12 on Windows 64 bit, I got an error when siplib was linked.
The symbol sipSetBool was missing.

The generated sip\siplib\setup.py has these lines, but the file content is not used when building with waf:

if sys.platform == 'win32':
    module_src.append('bool.cpp')

This PR adds bool.cpp also to wscript.

[swt2c]

bool.cpp was removed in sip 6.8.5. Is there some reason you can't use sip 6.8.5?

[DietmarSchwertberger]

Thanks. This was not intentional. I thought build.py would check for correct prerequisites?

[swt2c]

Thanks. This was not intentional. I thought build.py would check for correct prerequisites?

It does for some things that it depends on (like doxygen and waf) but not for python dependencies, unfortunately as those kind of need to be installed outside of its purview. We could probably do something like that if we add a pyproject.toml, but that would mostly work for the but I'm not sure about using build.py directly.