Please read the release notes at https://github.com/JoinMarket-Org/joinmarket-clientserver/blob/master/docs/release-notes/release-notes-0.9.10.md for details on what this release includes.
This release includes removal of Python 3.6 (which had been end-of-life since end of 2021), so now Python 3.7+ is minimum requirement.
This release also includes signalling BIP125 opt-in RBF all non-coinjoin send transactions by default and bumpfee.py script to create RBF replacements to speed up unconfirmed transactions. And fee estimator will now only randomize transaction fee rate upwards, not below block target estimation or manually set fee rate.
There is new RPC API endpoints, handling of BIP21 bitcoin: URIs with multiple duplicating keys and various bugfixes and minor changes.
Note that this release is signed by Kristaps Kaupe not Adam Gibson.