Add github actions test to validate images in release_versions

Hi,

We have release_versions file in PXC and PSMDB (will be added for PG also) that stores images. If there is a misprint somewhere in images - the error will be populated to all release images and we will not know about it till we start jenkins tests. It makes sense to add some github actions test verify images when the file is updated (for example run docker manifest inspect)