test: remove performance sensitive test

A test must not fail depending on the performance of the machine it
runs on. It creates false negative and serves no purpose. These are
not benchmark tests for the hardware running them.

modules/cache/cache_test.go

@@ -9,7 +9,6 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/modules/setting"
-	"code.gitea.io/gitea/modules/test"
 
 	"github.com/stretchr/testify/assert"
 )
@@ -35,18 +34,6 @@ func TestNewContext(t *testing.T) {
 	assert.Nil(t, con)
 }
 
-func TestTest(t *testing.T) {
-	defer test.MockVariableValue(&conn, nil)()
-	_, err := Test()
-	assert.Error(t, err)
-
-	createTestCache()
-	elapsed, err := Test()
-	assert.NoError(t, err)
-	// mem cache should take from 300ns up to 1ms on modern hardware ...
-	assert.Less(t, elapsed, SlowCacheThreshold)
-}
-
 func TestGetCache(t *testing.T) {
 	createTestCache()