v0.4.22

Unfortunately the introduction of the iana-time-zone dependency in 0.4.21 caused some new regressions with lesser known platforms. This release fixes all of the issues we've encountered, improving the situation on some WebAssembly targets, SGX and on macOS/iOS. We've improved our CI setup to hopefully catch more of these issues before release in the future.

• Make wasm-bindgen optional on wasm32-unknown-unknown target (#771)
• Avoid iana-time-zone dependency on x86_64-fortanix-unknown-sgx (#767, thanks to @trevor-crypto)
• Update iana-time-zone version to 0.1.44 to avoid cyclic dependencies (#773, thanks to @Kijewski for the upstream PRs)
• Clarify documentation about year range in formatting/parsing (#765)