Build system is not setup to continue to release 1.x.x versions

[wholtz]

Micromamba v1.5.11 was just released. Our build system only tries to build the most recent version, so it will not attempt any version 1.x build. Do we care?

I made a v1.5.11 branch, that I could manually kick off the build pipeline on, but this will overwrite several tags including latest, so it would take some pipeline modifications.

[maresb]

I think they've solved most of the regressions in v2 in main, so I am hoping that when v2.0.4 is released it will make v1 mostly obsolete. I think a lazy only-if-needed approach v1 releases is perfectly justifiable.