don't filter action run on semver

[maxheld83]

total nitpick, but:

    tags:
      - "v?[0-9]+.[0-9]+.[0-9]+*"

... isn't this (= whether the tag is valid semver and what to do if not) a concern for the https://github.com/DeterminateSystems/flakehub-push action?

If, for example, I fumble the git tag -a v.a.b.c, I'd rather have the action still run, and then (possibly) have the push to FlakeHub fail, if FlakeHub requires semantic versioning.

So I'd suggest just removing that line from the example workflow uses.

(Or I'd be curious to know why we should filter already at the GHA workflow run level).