fix workflow part XIV

Author: HenriWahl

.github/workflows/build-release-latest.yml

@@ -4,11 +4,6 @@ on:
     tags-ignore: 'v*'
     branches: '*'
 
-env:
-  # ERROR: failed to build: invalid tag "ghcr.io/HenriWahl/checkmk-agent-plugin-yum/build:build-image": repository name must be lowercase
-  # this is the penalty for using uppercase letters in repository names...
-  cr_image: ghcr.io/henriwahl/checkmk-agent-plugin-yum/build
-
 jobs:
   build-image:
     runs-on: ubuntu-latest
@@ -22,10 +17,10 @@ jobs:
           registry: ghcr.io
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
-      # somehow weird way to get the hash over the requirements to be aware if they changed
       - id: get_hash
         run: echo "HASH=$(ls -lR | xargs | md5sum | cut -d\  -f1)" >> $GITHUB_OUTPUT
-      - run: echo "Computed hash ${{ steps.get_hash.outputs.HASH }}"
+      - id: get_image
+        run: echo "(${{ github.repository }} | tr '[:upper:]' '[:lower:]'):${{ steps.get_hash.outputs.HASH }}"
       # build container image for package creation
       - run: docker pull ${{ env.cr_image }}:${{ steps.get_hash.outputs.HASH }} || docker build -t ${{ env.cr_image }}:${{ steps.get_hash.outputs.HASH }} -f dockerfiles/checkmk/Dockerfile .
       - run: docker push ${{ env.cr_image }}:${{ steps.get_hash.outputs.HASH }}