* Automate more of Wasmtime's release process
This change revamps the release process for Wasmtime and intends to make
it nearly 100% automated for major release and hopefully still pretty
simple for patch releases. New workflows are introduced as part of
this commit:
* Once a month a PR is created with major version bumps
* Specifically hinted commit messages to the `main` branch will get
tagged and pushed to the main repository.
* On tags we'll now not only build releases after running CI but
additionally crates will be published to crates.io.
In conjunction with other changes this means that the release process
for a new major version of Wasmtime is simply merging a PR. Patch
releases will involve running some steps locally but most of the
nitty-gritty should be simply merging the PR that's generated.
* Use an anchor in a regex