Integrate "version bump" into rattler-build

[wolfv]

I think it would be cool if we could automate version bumping in rattler-build.

There could be two modes:

• supply a known version – then rattler-build will insert it, and find out the new "hash"
• Know about a few URLs (similar to the autotick-bot). For example, for a Github URL we can grab the RSS feed and figure out the latest versions from that. The autotick bot also does some clever request "probing" by trying to increment the patch, minor and major versions to find if there is a new file available.

After bumping, rattler-build should write out the new recipe.

[orhun]

I use the next_version crate for git-cliff's --bump option. Not sure if it is useful, just my 2 🪙s

[pavelzw]

Something like brew bump-formula-pr would be cool. They also take care of forking the repo, creating the PR etc.