chore(deps): update github.com/prometheus/client_golang to v1.21.1#6433

dmathieu merged 2 commits intoopen-telemetry:mainopen-telemetry/opentelemetry-go:mainfrom

ajatprabha:update-prometheus-clientajatprabha/opentelemetry-go:update-prometheus-clientCopy head branch name to clipboard