Re-add final to types that reasonably should never need subclassing /… #1928

All 1 919 tests pass, 1 skipped in 1m 3s

18 files ±0 18 suites ±0 1m 3s ⏱️ +2s
1 920 tests ±0 1 919 ✅ ±0 1 💤 ±0 0 ❌ ±0
2 536 runs ±0 2 534 ✅ ±0 2 💤 ±0 0 ❌ ±0

Results for commit 907fe7d. ± Comparison against earlier commit 4a9d982.