feat!: add promise-based return assertions, do not auto-resolve returned promises #9535

Job	Run time
test-browser-windows (chrome, chromium)	5m 49s
test (ubuntu-latest, 18)	9m 50s
test-browser-windows (edge, webkit)	5m 42s
lint	1m 6s
test (ubuntu-latest, 20)	9m 33s
test-browser (chrome, chromium)	2m 58s
test-browser (firefox, firefox)	3m 33s
test (macos-14, 20)	5m 45s
test-ui (ubuntu-latest)	1m 53s
test-browser (edge, webkit)	3m 5s
test (windows-latest, 20)	9m 43s
test-ui (macos-14)	1m 58s
test-ui (windows-latest)	2m 45s
	1h 3m 40s

Provide feedback