ddtrace/tracer: add integration tag to spans_started/finished #3849

Job	Run time
Prepare Go modules cache	47s
Smoke Tests	0s
macos-13 go1.23	4m 56s
macos-13 go1.22	8m 37s
macos-15 go1.23	3m 38s
macos-15 go1.22	4m 7s
macos-latest (AppSec disabled)	2m 0s
windows-latest (AppSec disabled)	3m 3s
ubuntu-latest-16-cores (AppSec disabled)	1m 8s
linux/amd64 golang:1.23-bookworm	1m 37s
linux/arm64 golang:1.23-bookworm	2m 58s
linux/amd64 golang:1.23-bullseye	1m 20s
linux/arm64 golang:1.23-bullseye	3m 27s
linux/amd64 golang:1.23-alpine	1m 18s
linux/arm64 golang:1.23-alpine	3m 6s
linux/amd64 golang:1.22-bookworm	1m 22s
linux/arm64 golang:1.22-bookworm	3m 12s
linux/amd64 golang:1.22-bullseye	1m 20s
linux/arm64 golang:1.22-bullseye	3m 7s
linux/amd64 golang:1.22-alpine	1m 28s
linux/arm64 golang:1.22-alpine	3m 3s
	55m 34s

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