Removed centos build (as it is not supported)

Author: fabiocicerchia

.github/workflows/main.yml

@@ -17,7 +17,7 @@ jobs:
   docker_build:
     strategy:
       matrix:
-        distro: [alpine, amazonlinux, centos, debian, fedora, ubuntu]
+        distro: [alpine, amazonlinux, debian, fedora, ubuntu]
 
     name: Build Docker
     runs-on: ubuntu-20.04
@@ -70,13 +70,6 @@ jobs:
           name: metadata-amazonlinux
           path: docs/metadata
 
-      - name: Restore centos metadata artifacts
-        continue-on-error: true
-        uses: actions/download-artifact@v2
-        with:
-          name: metadata-centos
-          path: docs/metadata
-
       - name: Restore debian metadata artifacts
         continue-on-error: true
         uses: actions/download-artifact@v2