Remove support for EL7 and EL8 (but not OL8).

Author: mfeit-internet2

.github/workflows/docker-publish.yml

@@ -24,7 +24,7 @@ jobs:
     strategy:
       fail-fast: true
       matrix:
-        os: [ 'el7', 'el8', 'ol8',  'el9', 'd10','d11', 'd12', 'u18', 'u20', 'u22', 'u24' ]
+        os: [ 'ol8', 'el9', 'd10','d11', 'd12', 'u18', 'u20', 'u22', 'u24' ]
 
     runs-on: ubuntu-latest
     permissions:
@@ -72,7 +72,7 @@ jobs:
       # https://github.com/docker/build-push-action
       - name: Build and push Docker images
         id: build-and-push
-        if: ${{ matrix.os == 'el7' || matrix.os == 'el8' || matrix.os == 'ol8' || matrix.os == 'el9' }}
+        if: ${{ matrix.os == 'ol8' || matrix.os == 'el9' }}
         uses: docker/build-push-action@v3
         with:
           context: .