Only launch ssh agent if ssh keys are mounted in tekton.

task/buildkit-rootless-daemonless/0.1/buildkit-rootless-daemonless.yaml

@@ -77,9 +77,13 @@ spec:
         #!/usr/bin/env sh
         #
         set -euo pipefail
+        if [ -n "\$(find /tekton/creds/.ssh -maxdepth 1 -name 'id_*' -print -quit)" ]; then
             eval \$(ssh-agent)
             ssh-add /tekton/creds/.ssh/id_*
             exec buildctl-daemonless.sh build --ssh default=\$SSH_AUTH_SOCK "\${@}"
+        else
+            exec buildctl-daemonless.sh build "\${@}"
+        fi
         EOF
         chmod +x /home/user/.config/buildkit/entrypoint.sh
       volumeMounts: