runtime: skip TestCgoPprofCallback in short mode, don't run in parallel

Fixes #54778

Change-Id: If9aef0c06b993ef2aedbeea9452297ee9f11fa06
Reviewed-on: https://go-review.googlesource.com/c/go/+/460461
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>

src/runtime/crash_cgo_test.go

@@ -218,7 +218,9 @@ func TestCgoCCodeSIGPROF(t *testing.T) {
 }
 
 func TestCgoPprofCallback(t *testing.T) {
-	t.Parallel()
+	if testing.Short() {
+		t.Skip("skipping in short mode") // takes a full second
+	}
 	switch runtime.GOOS {
 	case "windows", "plan9":
 		t.Skipf("skipping cgo pprof callback test on %s", runtime.GOOS)