use checkout to get short sha

.github/workflows/build-push-image.yml

@@ -12,6 +12,13 @@ jobs:
       packages: write
 
     steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Add sha to GITHUB_OUTPUT
+        id: git-sha-short
+        run: echo "sha=$(git rev-parse --short HEAD)" >> $GITHUB_OUTPUT
+
       - name: Setup Buildx
         uses: docker/setup-buildx-action@988b5a0280414f521da01fcc63a27aeeb4b104db # v3.6.1
 
@@ -22,17 +29,6 @@ jobs:
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
-      - name: Extract branch name
-        id: git-branch
-        shell: bash
-        run: echo "branch=${GITHUB_HEAD_REF:-${GITHUB_REF#refs/heads/}}" >> $GITHUB_OUTPUT
-
-      - name: Get git sha
-        id: git-sha-short
-        # this command requires git checkout. Want to avoid. Trying calling gh api
-        # run: echo "sha=$(git rev-parse --short HEAD)" >> $GITHUB_OUTPUT
-        run: echo sha=$(cut -c 1-7 <<< `gh api "repos/${{ github.repository }}/commits/${{steps.git-branch.outputs.branch}}" --jq .sha`) >> $GITHUB_OUTPUT
-
       - name: Configure remote
         id: remote
         run: |