add `adoptedStyleSheets` fallback for older safari #11301

All 1 193 tests pass in 3m 29s

1 files ±0 133 suites ±0 3m 29s ⏱️ -5s
1 193 tests ±0 1 193 ✅ ±0 0 💤 ±0 0 ❌ ±0
1 215 runs ±0 1 215 ✅ ±0 0 💤 ±0 0 ❌ ±0

Results for commit 3465877. ± Comparison against earlier commit c806c11.