Ensure valid output from `parseColorWithCache` (#9362)
Ensure valid output from `parseColorWithCache` (#9362)

- The new behavior doesn't work on `try { ... } catch { ... }`, so instead check if the output isn't null.
- Regressed from #9337
- Resolves #9356
darkreader/darkreader,darkreader/darkreader,darkreader/darkreader