Check for latest release on v7 branch

Author: kdambekalns

.github/workflows/docker.build.yaml

@@ -14,7 +14,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: main
+          ref: 'v7'
           fetch-depth: 100
 
       - name: Determine latest version
@@ -105,7 +105,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: 'main'
+          ref: 'v7'
           fetch-depth: 100
 
       - name: Determine latest version