2026-02-12 release announcement draft

Hi,

Please see the proposed draft of the 2026-02-12 announcement. Please 
review for errors, typos, notable omissions, etc.

I also wanted to ensure I captured the correct set of post-upgrade steps 
for the `ltree` issue. I tried to simplify it as much as possible while 
trying to convey how narrow the scope of having to reindex. However, if 
I. misunderstood, please help me correct.

Thanks,

Jonathan