py(deps[dev]) starlette 1.4.0 -> 1.6.0

why: Two minors of the ASGI layer. 1.5.0 is entirely `GZipMiddleware`:
it gains an `exclude_content_types` parameter, flushes output per
streamed chunk rather than buffering, skips compression of partial (206)
responses, and widens the default excluded content types. 1.6.0 adds
`max_body_size` to `Starlette` and the route classes, giving a request
body limit that previously had to be enforced by hand, and exposes
`http.response.debug` information through response extensions.

what:
- uv.lock: starlette 1.4.0 -> 1.6.0

See also:
- https://github.com/encode/starlette/releases/tag/1.5.0
- https://github.com/encode/starlette/releases/tag/1.6.0

Author: tony