contrib/envoyproxy: envoy external processing support #3299

Job	Run time
Prepare Go modules cache	16s
Smoke Tests	0s
macos-12 go1.23	6m 19s
macos-12 go1.22	10m 17s
macos-14 go1.23	4m 17s
macos-14 go1.22	5m 14s
macos-latest (AppSec disabled)	2m 8s
linux/amd64 golang:1.23-bookworm	1m 33s
windows-latest (AppSec disabled)	3m 12s
ubuntu-latest-16-cores (AppSec disabled)	1m 17s
linux/arm64 golang:1.23-bookworm	3m 7s
linux/amd64 golang:1.23-bullseye	1m 31s
linux/arm64 golang:1.23-bullseye	3m 6s
linux/amd64 golang:1.23-alpine	1m 18s
linux/arm64 golang:1.23-alpine	3m 5s
linux/amd64 golang:1.22-bookworm	1m 32s
linux/arm64 golang:1.22-bookworm	3m 13s
linux/amd64 golang:1.22-bullseye	1m 24s
linux/arm64 golang:1.22-bullseye	3m 18s
linux/amd64 golang:1.22-alpine	1m 33s
linux/arm64 golang:1.22-alpine	2m 56s
	1h 0m 36s

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