MSVC 7 project files don't exist any longer, so don't try updating them
in upmake.
This should have been done in 8b854d2f92 (Remove MSVC 7 project files
and support for generating them, 2021-04-26).
A recent commit added the file src/stc/PlatWXcocoa.mm needed for wxSTC
with the cocoa port. This commit modifies the build system files to
use this new file when it is needed.
Replace the specialized Python script used for it before (and which was
actually forgotten to run a couple of times already) with a newer
version of upmake, which can now update CMake variable definitions too.
This message shouldn't be given only when --verbose is given, it's
useful as a reminder and you shouldn't have to remember to give a
special option to get this reminder.
Update the old style MSVC project files for wxWidgets itself (but not the
samples etc) from upmake instead of bakefile too, as the latest upmake version
can handle them.
Remove the Perl modules composing upmake from wxWidgets repository, it's too
difficult to maintain them both here and at https://github.com/vadz/upmake and
just keep the wxWidgets-specific upmake_script.pl here and generate
build/upmake_script itself from it using fatpack.
This also updates upmake to the latest 0.3 version, as a side effect.
