Revert "chore: bump int128/docker-manifest-create-action from 1 to 2"

[MatteoVoges]

Reverts #1107

v2 does not support suffixes anymore and goes with a new sources approach, where you would define the links to the image via digest. Wit hour current matrix strategy its hard to retrieve the digest per image / per platform. So let's rollback for now!

Guide to migrate by action owner:

Migration from V1 to V2

This action no longer supports the suffixes input.
You need to set an image URI with a digest or tag.
If you use docker/build-push-action, you can construct an image URI from the outputs as follows:

- uses: docker/build-push-action@v5
  id: build-amd64
  with: # ...omit...
- uses: docker/build-push-action@v5
  id: build-arm64
  with: # ...omit...

- uses: int128/docker-manifest-create-action@v2
  with:
    tags: ghcr.io/${{ github.repository }}:main
    sources: |
      ghcr.io/${{ github.repository }}@${{ steps.build-amd64.outputs.digest }}
      ghcr.io/${{ github.repository }}@${{ steps.build-arm64.outputs.digest }}

[MatteoVoges]

CI depends on #1125