DAOS-13684 test: Bump docker nlt system_ram_reserved (#12432) (#12471)

Increase system RAM reservation when calculating tmpfs size in NLT
docker tests to avoid intermittent available memory check failures on
engine start due to memory contention across multiple containers on
the same host.

Signed-off-by: Tom Nabarro <tom.nabarro@intel.com>

ci/docker_nlt.sh

@@ -22,7 +22,7 @@ pushd "$TMP_DIR"
 set +e
 
 sudo --preserve-env=VIRTUAL_ENV,PATH ./node_local_test.py \
- --no-root --memcheck no --system-ram-reserved 32 --server-debug WARN "$@"
+ --no-root --memcheck no --system-ram-reserved 48 --server-debug WARN "$@"
 
 RC=$?
 set -e