Upgrade headers to 0.4.0 (#2351) #4065

Job	Run time
cargo-hack	3m 18s
check	54s
check-docs	28s
cargo-public-api-crates (axum)	1m 2s
cargo-public-api-crates (axum-core)	47s
cargo-deny check (advisories)	25s
cargo-public-api-crates (axum-extra)	56s
cargo-deny check (bans licenses sources)	25s
dependencies-are-sorted	20s
Spell Check with Typos	4s
cargo-public-api-crates (axum-macros)	46s
test-versions (stable)	2m 22s
test-nightly	1m 46s
test-docs	1m 57s
test-versions (beta)	2m 26s
armv5te-unknown-linux-musleabi	48s
wasm32-unknown-unknown	32s
test-msrv	7m 8s
	26m 24s

Provide feedback