Merge pull request #18243 from ssahani/ensure-put-use

tree-wide: introduce hashmap_ensure_put() and use it

diff --cc src/network/networkd-address-label.c
Simple merge

diff --cc src/network/networkd-mdb.c
Simple merge

diff --cc src/network/networkd-nexthop.c
Simple merge

diff --cc src/network/networkd-route.c
Simple merge

diff --cc src/network/networkd-routing-policy-rule.c
Simple merge