CI builds does not take into account RC builds when tagging packages

[fmartingr]

Describe the bug / actual behavior

The CI uses conditionals to check if the released version is a development version or not (that is, if pushed to a v* tag or not).

When tagging the images, the conditional need to check if the version is a rc version as well.

The workflow should be:

v* tag push to master:

• gorelease: ok ( build and publish v*)
• buildx: ok (publishv* and latest)

commit push to master:

• gorelease: ok (build v*)
• buildx: ok (publish v*-next-commit and dev)

v*-rc* push to master:

• gorelease: (build and publish v*-rc*)
• buildx: build and publish with v*-rc* but not with latest nor dev.

Links

• Gorelease CI: https://github.com/go-shiori/shiori/blob/master/.github/workflows/_gorelease.yml#L16
• Buildx CI: https://github.com/go-shiori/shiori/blob/master/.github/workflows/_buildx.yml#L26-L38