cleanup of build file, added latest tag for main

.gitea/workflows/02_build.yaml

@@ -29,14 +29,9 @@ jobs:
             git.fai.st/fedi-image-bot/bot-api            
           # generate Docker tags based on the following events/attributes
           tags: |
-            type=schedule
+            type=raw,value=latest,enable=${{ github.ref == format('refs/heads/{0}', 'main') }}
             type=ref,event=branch
-            type=ref,event=pr
             type=sha            
-#      - name: Set up QEMU
-        # Add support for more platforms with QEMU (optional)
-        # https://github.com/docker/setup-qemu-action
-#        uses: docker/setup-qemu-action@v2
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v2
       - name: Login to fai.st docker registry