chore: drop unused cf-connecting-ipv6 header #3480

Job	Run time
tests / Playwright Legacy Tests (chromium)	4m 28s
tests / Playwright Tests (chromium)	3m 4s
tests / Playwright Legacy Tests (firefox)	4m 26s
tests / Playwright Tests (firefox)	6m 6s
tests / Python Tests	29m 13s
	47m 17s

Provide feedback