Fix retry

Merge branch 'main' into proxyman

Use Proxyman packages

Use Proxyman packages

Add link to examples folder in root README.md (swift-server#556)

Fix race between connection close and scheduling new request (swift-s…

…erver#546) (swift-server#548)

Add h2 stream integration tests (swift-server#502)

Always overwrite `Transport-Encoding` and `Content-Length` headers (s…

…wift-server#479)

Only crash in debug mode, if HTTPClient was not shutdown (swift-serve…

…r#478)

### Motivation

Generally we want to inform users that they need to shutdown their HTTPClient. Until `1.6.0` we did this with an assert in HTTPClient's deinit. With `1.6.0` this behavior was raised to a precondition. Because of this adopters might suddenly crash in production where they didn't before.

### Changes

- This pr reverts the current behavior back to something pre `1.6.0`

### Result

- HTTPClient doesn't crash in production anymore.

Support informational response heads (swift-server#469)