Try to fix step "Test ssh connectivity": ssh localhost instead of openssh

Signed-off-by: Jiahao XU <Jiahao_XU@outlook.com>

Author: NobodyXu

.github/workflows/coverage.yml

@@ -33,7 +33,7 @@ jobs:
           sleep 30
           chmod 600 .test-key
           mkdir /tmp/openssh-rs
-          ssh -i .test-key -v -p 2222 -l test-user openssh -o StrictHostKeyChecking=accept-new -o UserKnownHostsFile=/tmp/openssh-rs/known_hosts whoami
+          ssh -i .test-key -v -p 2222 -l test-user localhost -o StrictHostKeyChecking=accept-new -o UserKnownHostsFile=/tmp/openssh-rs/known_hosts whoami
         name: Test ssh connectivity
       - run: |
           eval $(ssh-agent)