This test started failing recently in older versions of React because
the Scheduler priority inside a microtask is Normal instead of
Immediate. This is expected because microtasks are not Scheduler tasks;
it's an implementation detail.
I gated the test to only run in v17 because it's a regression test for
legacy Suspense behavior, and the implementation details of the snapshot
changed in v18.
Test plan
---------
Using latest:
```
yarn test --build --project devtools --release-channel=experimental profilingcache
```
Using v17 (typically runs in a timed CI workflow):
```
/scripts/circleci/download_devtools_regression_build.js 17.0 --replaceBuild
yarn test --build --project devtools --release-channel=experimental --reactVersion 17.0 profilingcache
```