emulators/wine-devel: Update to Wine 6.21

This includes the following changes:

• WinSpool, GPhoto, and a few other modules converted to PE.
• Better support for inline functions in DbgHelp.
• Beginnings of a MSDASQL implementation.
• Various bug fixes.

files/patch-dlls-winebus-6.20 and files/patch-no-procfs have been
accepted upstream, so remove our local copies.

With that, and additional upstream changes, mounting /proc is no
longer required on FreeBSD, so we don't need to document it. [1]

PR: 258795 [1]
Approved by: maintainer (= author)