contrib/gocql/gocql: implement observer api based tracing #2819

Job	Run time
Prepare Go modules cache	54s
Smoke Tests	0s
macos-12 go1.22	5m 50s
macos-12 go1.21	6m 37s
macos-latest (AppSec disabled)	1m 38s
linux/amd64 golang:1.22-bookworm	1m 20s
macos-14 go1.22	3m 20s
linux/arm64 golang:1.22-bookworm	2m 57s
windows-latest (AppSec disabled)	2m 33s
macos-14 go1.21	3m 24s
ubuntu-latest-16-cores (AppSec disabled)	1m 12s
linux/amd64 golang:1.22-bullseye	1m 22s
linux/arm64 golang:1.22-bullseye	2m 38s
linux/amd64 golang:1.22-alpine	1m 18s
linux/arm64 golang:1.22-alpine	2m 41s
linux/amd64 golang:1.21-bookworm	1m 24s
linux/arm64 golang:1.21-bookworm	2m 49s
linux/amd64 golang:1.21-bullseye	1m 23s
linux/arm64 golang:1.21-bullseye	2m 56s
linux/amd64 golang:1.21-alpine	1m 16s
linux/arm64 golang:1.21-alpine	2m 38s
	50m 10s

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