Merge branch 'ep/test-malloc-check-with-glibc-2.34'

The method to trigger malloc check used in our tests no longer work with newer versions of glibc. * ep/test-malloc-check-with-glibc-2.34: test-lib: declare local variables as local test-lib.sh: Use GLIBC_TUNABLES instead of MALLOC_CHECK_ on glibc >= 2.34