Limit Container Branch tags to 128 characters

This is the docker imposed tag limit.

Signed-off-by: Trevor Bramwell <[email protected]>

Author: bramwelt

.github/workflows/ko-build-branch.yaml

@@ -30,7 +30,7 @@ jobs:
       - name: Prepare container tag
         id: container_tag
         run: |
-          export container_tag=$(echo ${{ github.head_ref }} |  sed 's/[^_0-9a-zA-Z]/\-/g')
+          export container_tag=$(echo ${{ github.head_ref }} |  sed 's/[^_0-9a-zA-Z]/\-/g' | cut -c -127)
           echo "tag=$container_tag" >> $GITHUB_OUTPUT
       - name: Build project-api for PR
         run: |