SwiftNIO HTTP/2 1.28.0

SemVer Minor

• Limit rate of permitted RST frames (3798fe5)

SemVer Patch

• Replace os() with canImport(Darwin) (#399, patch credit to @brennobemoura)
• Fix parent channel read() call on HTTP2StreamChannel initialization causing incorrect order of inbound HTTP2Frames (#413, patch credit to @qusc)
• Generic helpers for HTTP/2 async pipelines (#401)
• Inline http2 fixups (#402)
• H2 stream AsyncIterator non-sendable on 5.7 (#405)
• Delay stream creation until the next loop tick (#416)

Other Changes

• Update allocation limits (#400)
• HTTP/2 pipeline NIOAsyncChannel pipeline changes (#403) (#406) (#407) (#408) (#409) (#411) (#414) (#415) (#419)