Per-package release pins

[liamhuber]

update-pyproject-dependencies and the downstream .github/workflows/pyproject-release.yml currently allow us to specify how semantically-versioned packages should be pinned en-masse (with a default to pin things as strictly as possible, i.e. patch-level). It would be nice to be able to override this on a per-package basis. My current thought is to introduce three new inputs: per-package-semantic-patch/minor/major-upper-bound, which are space separated lists of package names that default to an empty string.

Concretely, this will allow us to release the pyiron_snippets pin to only hold major versions, as discussed in today's team meeting.