contrib/grpc: attempt to fix flaky tests #2989

Job	Run time
Prepare Go modules cache	58s
Smoke Tests	0s
macos-latest (AppSec disabled)	1m 35s
macos-12 go1.23	5m 58s
windows-latest (AppSec disabled)	2m 44s
macos-12 go1.22	5m 37s
linux/amd64 golang:1.23-bookworm	1m 18s
ubuntu-latest-16-cores (AppSec disabled)	1m 16s
linux/arm64 golang:1.23-bookworm	2m 59s
macos-14 go1.23	2m 39s
macos-14 go1.22	3m 51s
linux/amd64 golang:1.23-bullseye	1m 32s
linux/arm64 golang:1.23-bullseye	3m 7s
linux/amd64 golang:1.23-alpine	1m 20s
linux/arm64 golang:1.23-alpine	2m 57s
linux/amd64 golang:1.22-bookworm	1m 26s
linux/arm64 golang:1.22-bookworm	2m 50s
linux/amd64 golang:1.22-bullseye	1m 30s
linux/arm64 golang:1.22-bullseye	2m 57s
linux/amd64 golang:1.22-alpine	1m 18s
linux/arm64 golang:1.22-alpine	2m 45s
	50m 37s

Provide feedback