Fix 'failing/85 gtest dependency with version' test to fail on Arch
If gtest is patched to have a pkg-config file, that will report the
version, so force the 'system' method to be used when we are exercising
that an unknown version doesn't satisfy any version constraint.
project('gtest dependency with version', ['c', 'cpp'])
# discovering gtest version is not yet implemented
-dep = dependency('gtest', version: '>0')
+dep = dependency('gtest', method: 'system', version: '>0')
