Very minor update for Kusama that only affects the Relay Chain, Asset Hub, and People Chain. Mainly it cleans up some errors from the People Chain launch, removes anything Identity-related from the Relay Chain, and prepares Asset Hub for an upcoming change to asset indices.

Release notes: https://github.com/polkadot-fellows/runtimes/releases/tag/v1.2.6

Enactment set for 26 June.