neotest: test-go: Disable test results caching

Starting from Go1.10 `go test` caches successful test results[1].
However we want to torture the implementation and run the tests for real
each time `neotest test-go` is ran.

-> Disable tests caching

[1] https://golang.org/doc/go1.10#test

go/neo/t/neotest

@@ -139,7 +139,7 @@ $@
 
 # ---- go/py unit tests ----
 cmd_test-go() {
-	go test lab.nexedi.com/kirr/neo/go/...
+	go test -count=1 lab.nexedi.com/kirr/neo/go/... # -count=1 disables tests caching
 }
 
 cmd_test-py() {