Update docker.yml

simplify

Author: toniher

.github/workflows/docker.yml

@@ -52,15 +52,6 @@ jobs:
       - name: Sets env vars for Docker image
         run: |
           echo "DOCKER_IMAGE_BRANCH=${{ matrix.branch }}" >> $GITHUB_ENV
-        if: ${{ matrix.branch != 'main' }}
-      - name: Sets env vars for Docker image
-        run: |
-          echo "DOCKER_IMAGE_BRANCH=latest" >> $GITHUB_ENV
-        if: ${{ matrix.branch == 'main' }}
-      - name: Sets env vars for Docker image
-        run: |
-          echo "DOCKER_IMAGE_BRANCH=${{ matrix.branch }}" >> $GITHUB_ENV
-        if: ${{ matrix.branch != 'main' }}
       - name: Push Docker
         uses: docker/build-push-action@v3
         with: