test: increase history size of race condition detector

This commit increases the history size of the race condition detector
such that we will more reliably be able to recover the stack in the
case that a race condition occurs.

gotest.sh

@@ -77,7 +77,7 @@ test_race_conditions() {
     check_test_ports
     
     test_targets=$(go list ./... | grep -v '/vendor/')
-    env GORACE="halt_on_error=1" go test -v -race $test_targets
+    env GORACE="history_size=7 halt_on_error=1" go test -v -race $test_targets
 }
 
 # lint_check runs static checks.