Fixed -Wdeprecated-copy warnings in gtest. NFCI.
@xbolva00 Isn't the gtest code supposed to be taken from the upstream project? https://github.com/google/googletest
Do we have any local changes already?
They know about this issue https://github.com/google/googletest/issues/2224 but sadly, no progress.
For me, the priority is/was to make our bots green.