feat(test runner): rework how tsconfig is applied #22688

Job	Run time
ubuntu-22.04 (chromium - Node.js 18)	11m 41s
ubuntu-20.04 (chromium tip-of-tree)	11m 17s
ubuntu-22.04 (firefox - Node.js 18)	24m 39s
ubuntu-22.04 (webkit - Node.js 18)	15m 23s
Test Runner (ubuntu-latest, 18, 1, 2)	11m 49s
ubuntu-22.04 (chromium - Node.js 16)	11m 47s
ubuntu-22.04 (chromium - Node.js 20)	11m 40s
Test Runner (ubuntu-latest, 18, 2, 2)	14m 19s
VSCode Extension	7m 20s
Test Runner (windows-latest, 18, 1, 2)	17m 18s
Installation Test ubuntu-latest	10m 46s
Installation Test macos-latest	20m 30s
Test Runner (windows-latest, 18, 2, 2)	20m 23s
Installation Test windows-latest	16m 51s
Test Runner (macos-latest, 18, 1, 2)	14m 21s
Test Runner (macos-latest, 18, 2, 2)	31m 29s
Web Components	1m 51s
Test Runner (ubuntu-latest, 16, 1, 2)	11m 28s
Test Runner (ubuntu-latest, 16, 2, 2)	13m 38s
Test Runner (ubuntu-latest, 20, 1, 2)	10m 49s
Test Runner (ubuntu-latest, 20, 2, 2)	13m 39s
	5h 2m 58s

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