Fix GMock deprecation warnings

[christophfroehlich]

   /opt/ros/humble/src/gtest_vendor/include/gtest/internal/gtest-port.h:682:8: note: expanded from macro 'GTEST_DISALLOW_ASSIGN_'
    void operator=(type const &) = delete
         ^
  /opt/ros/humble/src/gmock_vendor/include/gmock/gmock-matchers.h:3660:10: note: in implicit copy constructor for 'testing::internal::FloatingEqMatcher<float>' first required here
    return internal::FloatingEqMatcher<float>(rhs, false);
           ^
  /opt/ros/humble/src/gmock_vendor/include/gmock/gmock-matchers.h:721:3: warning: definition of implicit copy constructor for 'StrEqualityMatcher<std::basic_string<char>>' is deprecated because it has a user-declared copy assignment operator [-Wdeprecated-copy]
    GTEST_DISALLOW_ASSIGN_(StrEqualityMatcher);