The new versions are 0.8.20, 0.8.21 and 0.8.22.

In terms of the language itself:

https://soliditylang.org/blog/2023/05/10/solidity-0.8.20-release-announcement

• N/A

https://soliditylang.org/blog/2023/07/19/solidity-0.8.21-release-announcement/

• Allow qualified access to events from other contracts.
• Relax restrictions on initialization of immutable variables. Reads and writes may now happen at any point at construction time outside of functions and modifiers. Explicit initialization is no longer mandatory.

https://soliditylang.org/blog/2023/10/25/solidity-0.8.22-release-announcement

• Allow defining events at file level - support Solidity v0.8.22 syntax #648