fixup! graphdb: add concurrent cache property

Author: Roasbeef

graph/db/store_concurrency_test.go

@@ -615,8 +615,6 @@ func TestStoreCacheConcurrentAccess(t *testing.T) {
 
 		select {
 		case <-done:
-		case <-time.After(3 * time.Second):
-			t.Fatalf("concurrent cache operations timed out")
 		}
 	})
 }