Remove building of `rattler-build` from python and into actions

[tdejager]

We need to have a clean ci env that does not contain a rattler-build:

• Use the latest main version and compile this from source.
• Use this to build the recipes.

Need to figure out where to/get the rattler-build and compile it from. Either just clone it somewhere or use a something smarter later.

[wolfv]

Just FYI, we released a version of rattler-build a while ago that fixed the reproducibility issues with .conda packages.