Penultimate round of db.DefaultContext refactor (#27414)

Part of #27065

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Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

models/repo_test.go

@@ -20,5 +20,5 @@ func TestCheckRepoStats(t *testing.T) {
 func TestDoctorUserStarNum(t *testing.T) {
 	assert.NoError(t, unittest.PrepareTestDatabase())
 
-	assert.NoError(t, DoctorUserStarNum())
+	assert.NoError(t, DoctorUserStarNum(db.DefaultContext))
 }