Bake workflow

[crazy-max]

needs #3237

Switch to buildx bake workflow to ease building and validating the project.

• bake targets
  • vendor / validate-vendor
  • authors / validate-authors
  • lint
  • binaries / binaries-cross
  • release
  • generated-files / validate-generated-files
  • shfmt / validate-shfmt
  • image / image-all
  • frontend / frontend-all (dockerfile)

hack/test is the only one that has not been touched for now but we can look at it in a follow-up.

[crazy-max]

There is a slight difference now when we want to release the Dockerfile frontend. Previously we had to push a tag for each channel like dockerfile/1.4.0, dockerfile/1.4.0-labs. Now you only have to push a single tag dockerfile/1.4.0 and this will release channels specified in this matrix.