Prepare for v2.47.0.windows.2 (#5221)

At the moment, the Git maintainer is on vacation. While there _is_ an
interim maintainer, it seems as if v2.47.1 will need to wait for "the
end of the month".

However, I do not have the luxury of waiting for the end of the month,
as #5199 is stacking up comments relating various degrees of upset over
the lack of a new Git for Windows version that fixes fetches/pushes via
SSH.

To make it truly worth the effort, let's integrate a couple of topics
that have been integrated into upstream Git's `master` and `next`
branches in the meantime, topics I consider important enough to be
fast-tracked into a new Git for Windows version, since we already have
the need for one:

- 53d9f27 Merge branch 'jh/config-unset-doc-fix'
  Fixes incorrect documentation
- a89881e Merge branch 'js/doc-platform-support-link-fix'
  Fixes broken links in the documentation
- 784986f Merge branch 'jk/fsmonitor-event-listener-race-fix'
  CI-only: fixes 6h timeouts in the `osx-*` jobs
- 59bf8d2 Merge branch 'ps/cache-tree-w-broken-index-entry' into
next
Fixes segmentation faults e.g. after a checkout failed due to invalid
filenames and there is now a half-valid Git index
- ffd5653 Merge branch 'pb/clar-build-fix' into next
I suspect that this might cause some flakiness in (parallel) CI builds,
even if I have not personally noticed those flakes.
- fe0f4bc Merge branch 'db/submodule-fetch-with-remote-name-fix'
into next
  Seems like a bug fix submodule users might want
- 6860bff Merge branch 'sk/msvc-warnings' into next
This _should_ only affect builds with MS Visual C (which Git for Windows
does not use for the official builds), it's still a good idea to do, if
only to align with upstream Git's code.

Author: dscho