fix(sockets): return right headers for request upgrade #2732

Job	Run time
build-with-samply / Security, License Check	22s
build-with-samply / Build (amd64)	1m 48s
build-with-samply / Build (amd64, sockets)	3m 13s
build-with-samply / Build (arm64)	2m 27s
build-with-samply / Build (arm64, sockets)	2m 41s
build-with-samply / Test	1m 4s
build-with-samply / Test (sockets)	58s
build-with-samply / Docker (beam-proxy) / Dockerize (beam-proxy)	49s
build-with-samply / Docker (beam-proxy) / Tidy GHCR images (samply/beam-proxy)	25s
build-with-samply / Docker (beam-broker, sockets) / Tidy GHCR images (samply/beam-broker)	23s
build-with-samply / Docker (beam-broker, sockets) / Dockerize (beam-broker) (-sockets)	1m 7s
build-with-samply / Docker (beam-broker) / Dockerize (beam-broker)	50s
build-with-samply / Docker (beam-broker) / Tidy GHCR images (samply/beam-broker)	26s
build-with-samply / Docker (beam-proxy, sockets) / Dockerize (beam-proxy) (-sockets)	44s
build-with-samply / Docker (beam-proxy, sockets) / Tidy GHCR images (samply/beam-proxy)	23s
	17m 40s

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