[ci] Use webfactory/ssh-agent

.github/actions/prepare-gpu/action.yml

@@ -20,8 +20,6 @@ runs:
     - name: Init submodules to ensure stimuli is located
       run: |
         conda activate ${{ env.conda-env-name-no-time }}-$(date --date "${{ env.workflow-timestamp }}" +%Y%m%d)-${{ inputs.toolchain }}
-        eval `ssh-agent -s`
-        ssh-add - <<< ${{ secrets.PRIVATE_SSH_KEY }}
         ./scripts/init-submodules-no-riscv-tools.sh --force
       shell: bash -leo pipefail {0}
 

.github/workflows/chipyard-run-tests-gpu.yml

@@ -121,6 +121,9 @@ jobs:
     needs: setup-complete
     runs-on: self-hosted
     steps:
+      - uses: webfactory/ssh-agent@v0.8.0
+        with:
+          ssh-private-key: ${{ secrets.PRIVATE_SSH_KEY }}
       - name: Delete old checkout
         run: |
             ls -alh .