Jackson 2.12.1 released

[Tatu Saloranta]

Happy New Year 2021!

So, Jackson 2.12.1 was just released: full change list at:

https://github.com/FasterXML/jackson/wiki/Jackson-Release-2.12.1

This addresses a few important issues in 2.12.0 (17 fixes listed), the
most important probably being:

https://github.com/FasterXML/jackson-databind/issues/2962

which could cause a regression in some cases where both factory-method
and constructor-based single-argument Creator methods existed.

While there are no security fixes, upgrade is strongly recommended;
our hope is that after this patch the release rate will go down and
it'll be 2-3 months until the next patch.

After this release, state of 2.x branches is as follows:

* 2.9 branch is now fully closed; support officially ending with
jackson-databind 2.9.10.8 micro-patch (and matching jackson-bom).
* Prior 2.x branches have already been closed
* 2.10 branch is not yet closed but full patch releases are unlikely
-- micro-patches possible, but not very likely
* 2.11 branch open, 2.11.4 might (but is not necessarily) be the last
full patch release
* 2.12 is the active maintenance branch
* 2.13 branch was created for developing the next minor version (see
https://github.com/FasterXML/jackson/wiki/Jackson-Release-2.13 for
planning)

As usual, please let us know of any new regressions.

-+ Tatu +-