Git smoke tests flaking

Seeing many PR runs failing with

```
1) git smoke test
opens notebook diff and file from active notebook editor:
Error: Timeout of 60000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves. (/Users/runner/work/vscode/vscode/extensions/git/out/test/smoke.test.js)
at listOnTimeout (node:internal/timers:605:17)
at processTimers (node:internal/timers:541:7)

2) git smoke test
rename/delete conflict:

AssertionError [ERR_ASSERTION]: Expected values to be strictly equal:

1 !== 0

+ expected - actual

-1
+0

at Context. (extensions/git/src/test/smoke.test.ts:203:10)
```

Example https://github.com/microsoft/vscode/actions/runs/30021957806/job/89256687013