Flaky: debug E2E misses the breakpoint on macOS #79

The debug E2E added in #76, Rstest debug launch hits a breakpoint with port 9229 occupied and cleans up after continue, failed once on macOS and passed on rerun.

• Run: https://github.com/rstackjs/rstack-editor/actions/runs/36577017621 (attempt 1, E2E (macos-latest)), on feat(vscode): support function names as test titles #78, whose change does not touch debugging or the workspace-1 fixture (string titles only).
• Failure: AssertionError [ERR_ASSERTION]: debuggee should stop at the breakpoint from the waitFor at e2e/rstest/suite/debug.test.ts:66. After the timeout the run is torn down (Rstest debug worker disconnected, [birpc] rpc is closed, cannot call "runTest").
• The same test passed in the previous four CI runs on that branch and on main.

To find out: whether the breakpoint is sometimes bound after the debuggee has already passed it (js-debug child auto-attach timing on macOS), or the waitFor timeout is too tight for a slow runner.