chore: expose expect matcher result on TestError #26996

Job	Run time
ubuntu-22.04 (chromium - Node.js 18)	3m 5s
ubuntu-20.04 (chromium tip-of-tree)	3m 6s
ubuntu-22.04 (firefox - Node.js 18)	3m 6s
ubuntu-22.04 (webkit - Node.js 18)	3m 5s
Test Runner (ubuntu-latest, 18, 1, 2)	3m 4s
ubuntu-22.04 (chromium - Node.js 20)	3m 11s
Test Runner (ubuntu-latest, 18, 2, 2)	3m 5s
ubuntu-22.04 (chromium - Node.js 22)	3m 5s
Test Runner (windows-latest, 18, 1, 2)	2m 57s
Test Runner (windows-latest, 18, 2, 2)	2m 58s
Test Runner (macos-latest, 18, 1, 2)	3m 7s
Test Runner (macos-latest, 18, 2, 2)	3m 9s
Test Runner (ubuntu-latest, 20, 1, 2)	3m 5s
Installation Test ubuntu-latest	3m 7s
Installation Test macos-latest	3m 7s
Installation Test windows-latest	3m 0s
Test Runner (ubuntu-latest, 20, 2, 2)	3m 4s
Test Runner (ubuntu-latest, 22, 1, 2)	3m 3s
VSCode Extension	3m 0s
Test Runner (ubuntu-latest, 22, 2, 2)	3m 4s
Web Components	1m 57s
	1h 3m 25s

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