h3i: API cleanup #5628

Job	Run time
quiche_ios (x86_64-apple-ios)	1m 6s
quiche	1m 9s
quiche_windows (x86_64-pc-windows-msvc)	2m 56s
quiche_ios (aarch64-apple-ios)	1m 11s
quiche_macos (macos-13)	1m 20s
quiche (boringssl-boring-crate)	1m 19s
quiche_windows (i686-pc-windows-msvc)	3m 1s
quiche_macos (macos-latest)	1m 5s
quiche (openssl)	1m 25s
quiche_windows (x86_64-pc-windows-gnu)	2m 57s
android_ndk_lts (aarch64-linux-android)	1m 4s
quiche_windows (i686-pc-windows-gnu)	3m 0s
docker	2m 20s
android_ndk_lts (armv7-linux-androideabi)	1m 1s
http3_test	47s
android_ndk_lts (x86_64-linux-android)	1m 13s
nginx (1.16.1)	58s
android_ndk_lts (i686-linux-android)	1m 8s
quiche_multiarch (aarch64-unknown-linux-gnu)	1m 32s
quiche_multiarch (armv7-unknown-linux-gnueabihf)	1m 42s
quiche_multiarch (i686-unknown-linux-gnu)	1m 31s
	33m 45s

Provide feedback