This marks some files as vendored or generated. There may be more
files around.
This should mostly change our language statistics on github, so it
probably isn't worth much trouble, but maybe it makes the stats
slightly more representative.

The scripts in those directories were used to build windows superpacks
and mac dmg files. We now release wheels for both of those platforms.
There is little overhead maintaining these scripts, but they are clutter
and will eventually bit rot if not used for current systems. So remove
them.

Merge conflicts due to the release notes has been an annoying
problem requiring a rebase of otherwise good PRs. The solution
here is to use the --union option when merging to those files.

Closes #8603.