Upstream has removed the atomics implementation of CMM_LOAD_SHARED and
CMM_STORE_SHARED as these can be used also with non-stdatomics types.
As we only use the CMM api with stdatomics types, we can restore the
previous behaviour to prevent ThreadSanitizer warnings.
Closes #5660
Merge branch '5660-use-atomics-for-CMM-api-with-thread-sanitizer' into 'main'
See merge request isc-projects/bind9!11288