Remove unused usings in avifallocationtest
diff --git a/tests/gtest/avifallocationtest.cc b/tests/gtest/avifallocationtest.cc
index ecf3350..e5224d0 100644
--- a/tests/gtest/avifallocationtest.cc
+++ b/tests/gtest/avifallocationtest.cc
@@ -8,10 +8,6 @@
 #include "aviftest_helpers.h"
 #include "gtest/gtest.h"
 
-using ::testing::Combine;
-using ::testing::Values;
-using ::testing::ValuesIn;
-
 namespace libavif {
 namespace {