Remove commit message from GitHub Actions

This is not being consumed anywhere, so can be removed.

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

.github/workflows/build.yml

@@ -29,9 +29,6 @@ jobs:
       - name: Get Repo Owner
         id: get_repo_owner
         run: echo ::set-output name=repo_owner::$(echo ${{ github.repository_owner }} | tr '[:upper:]' '[:lower:]')
-      - name: Get Commit Message
-        id: get_commit_message
-        run: echo ::set-output name=commit_message::$(git log -1 --pretty=%B 2>&1 | head -n 1)
       - name: Build ${{ matrix.svc }}
         uses: docker/build-push-action@v2
         with: