Release for v6.12 is about to begin

[Vincent St-Amour]

The release process for v6.12 will begin in about a week. If you
have any new features that you want in and are relatively close to
to being done, now is a good time to do that.

*PROCESS CHANGES*

In the interest of streamlining the release process, this release introduces
a few small changes to our usual process.

First, any updates to HISTORY files should be done during the regular merge
window, i.e., between the 7th and the 15th, i.e., before the start of testing.
If you're not sure whether you're responsible for HISTORY file updates, please
consult the release checklist [1].

Second, there will be a fixed end date to the testing period, on the 22nd.
Please complete the tests you're responsible for before that point. If you do
not, I will make a best effort attempt at running them myself, and the release
will proceed without your input. If you're not sure whether you're responsible
for portions of testing, please consult the release checklist [1].

If you are responsible for either of those, and either cannot meet these
deadlines, or would rather not participate in releases in the future, please
get in touch.

[1] https://github.com/racket/racket/wiki/Release-Checklist-6.12

Upcoming dates:
- 7th: Branch day
- 15th: Testing starts
- 22nd: Testing ends