core: avoid stale entries in the DNS manager for non-virtual devices
_dev_l3_register_l3cds() schedules a commit, but if the device has commit type NONE, that doesn't emit a l3cd-changed. Do it manually, to ensure that entries are removed from the DNS manager.
Related: b86388be ('core: avoid stale entries in the DNS manager') Fixes: 58287cbc ('core: rework IP configuration in NetworkManager using layer 3 configuration')