ci: retry vscode smoke test
Created by: tjkandala
Context: https://sourcegraph.slack.com/archives/C01LZKLRF0C/p1650013900276399
Our VS Code extension smoke test appears to be flaky, often due to the search panel webview not rendering in time. I believe this is because we're making real requests to sourcegraph.com (for settings, for example) and we show a loading spinner until we receive all responses.
We have an integration test harness (#33921) with mock API responses soon to be merged that will replace the smoke test. If my theory is correct, we won't observe flakes anymore and we can remove the automatic retries.
Test plan
n/a