ci: set GOTOOLCHAIN=local for unit tests #2872

Job	Run time
Prepare Go modules cache	12s
Smoke Tests	0s
macos-latest (AppSec disabled)	1m 37s
macos-12 go1.22	5m 44s
linux/amd64 golang:1.22-bookworm	1m 27s
windows-latest (AppSec disabled)	2m 46s
macos-12 go1.21	7m 12s
linux/arm64 golang:1.22-bookworm	2m 56s
macos-14 go1.22	3m 22s
ubuntu-latest-16-cores (AppSec disabled)	1m 7s
linux/amd64 golang:1.22-bullseye	1m 20s
macos-14 go1.21	2m 55s
linux/arm64 golang:1.22-bullseye	2m 55s
linux/amd64 golang:1.22-alpine	1m 15s
linux/arm64 golang:1.22-alpine	2m 38s
linux/amd64 golang:1.21-bookworm	1m 27s
linux/arm64 golang:1.21-bookworm	3m 4s
linux/amd64 golang:1.21-bullseye	1m 19s
linux/arm64 golang:1.21-bullseye	2m 57s
linux/amd64 golang:1.21-alpine	1m 15s
linux/arm64 golang:1.21-alpine	2m 47s
	50m 15s

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