do not save variable when all we want is the side effect of popping it

It's redefined on every loop iteration, and as the comment says, we just
want to make sure the next loop skips a value.

unittests/allplatformstests.py

@@ -919,7 +919,7 @@ class AllPlatformTests(BasePlatformTests):
             wcc = compiler_from_language(env, lang, MachineChoice.HOST)
             wlinker = detect_static_linker(env, wcc)
             # Pop it so we don't use it for the next detection
-            evalue = os.environ.pop('AR')
+            os.environ.pop('AR')
             # Must be the same type since it's a wrapper around the same exelist
             self.assertIs(type(cc), type(wcc))
             self.assertIs(type(linker), type(wlinker))