fix: keep raw header name #13576

Job	Run time
Lint	29s
dependency-review	10s
Fuzzing	3m 27s
Test TypeScript types	29s
Test with Node.js 20 compiled --without-intl	5m 45s
Test with Node.js 21 compiled --without-intl	5m 9s
test (18, macos-latest) / Test with Node.js 18 on macos-latest	2m 47s
test (18, ubuntu-latest) / Test with Node.js 18 on ubuntu-latest	3m 2s
test (18, windows-latest) / Test with Node.js 18 on windows-latest	5m 26s
test (20, ubuntu-latest) / Test with Node.js 20 on ubuntu-latest	3m 28s
test (20, windows-latest) / Test with Node.js 20 on windows-latest	5m 33s
test (21, macos-latest) / Test with Node.js 21 on macos-latest	2m 54s
test (20, macos-latest) / Test with Node.js 20 on macos-latest	2m 51s
test (21, ubuntu-latest) / Test with Node.js 21 on ubuntu-latest	2m 42s
test (21, windows-latest) / Test with Node.js 21 on windows-latest	4m 56s
automerge	0s
	49m 8s

Provide feedback