test_cppext fails on s390x RHEL7 Refleaks 3.x: option ‘-std=gnu11’ is valid for C/ObjC but not for C++ (GCC 4.8.5)

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s390x RHEL7 Refleaks 3.x: https://buildbot.python.org/all/#/builders/129/builds/828

test test_cppext failed -- multiple errors occurred; run in verbose mode for details
(...)
      gcc -std=gnu11 -pthread -fno-strict-overflow -Wsign-compare -g -Og -Wall -fPIC -I/home/dje/cpython-buildarea/3.x.edelsohn-rhel-z.refleak/build/build/test_python_34724æ/test_python_worker_42721æ/tempcwd/env/include -I/home/dje/cpython-buildarea/3.x.edelsohn-rhel-z.refleak/build/Include -I/home/dje/cpython-buildarea/3.x.edelsohn-rhel-z.refleak/build -c /home/dje/cpython-buildarea/3.x.edelsohn-rhel-z.refleak/build/Lib/test/_testcppext.cpp -o build/temp.linux-s390x-cpython-313-pydebug/home/dje/cpython-buildarea/3.x.edelsohn-rhel-z.refleak/build/Lib/test/_testcppext.o -Werror -std=c++03
      cc1plus: error: command line option ‘-std=gnu11’ is valid for C/ObjC but not for C++ [-Werror]
      cc1plus: all warnings being treated as errors
      error: command '/usr/bin/gcc' failed with exit code 1

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test.pythoninfo:

CC.version: gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-44)

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Maybe I can just skip the test on old GCC versions, like GCC 4.8.

@stratakis: Do we care about testing C++ support of Python 3.13 on RHEL7?

[dtrodrigues]

This appears to be a dupe of #105776 introduced by #104925

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Ok, I close this issue, let's continue in issue #105776.