www-apps/mattermost-server: re-add and upgrade, fix #3

[lkraav]

This partially reverts commit 6feefc3.

I think Go 1.22 could be set as DEPEND?

[matoro]

Wow, let me apologize for letting this sit for two months - I somehow completely missed it in my notifications. I confirmed that after bumping to the latest this builds on my powerpc box. I've readded it to the repo and should be able to start fully maintaining this again - although I will only be checking for build success; nothing at runtime.

[lkraav]

Wow, let me apologize for letting this sit for two months - I somehow completely missed it in my notifications. I confirmed that after bumping to the latest this builds on my powerpc box. I've readded it to the repo and should be able to start fully maintaining this again - although I will only be checking for build success; nothing at runtime.

Np. 9.9 has been running well on this end. Next interesting challenge will be when they phase out MySQL / MariaDB support in MM 11.