This version updates openzeppelin-contracts, a transitive dependency of flexible-voting, to v4.9.3. This was the last version of the OpenZeppelin contracts in the v4.x series. A future of version of Flexible Voting will be released with compatibility for OpenZeppelin v5.x.
This release does not change any code in the core Flexible Voting code, i.e. the GovernorCountingFractional contract or the FlexibleVotingClient contract. Upgrading should be safe in all cases, except when you are depending on a part of OpenZeppelin—through Flexible Voting—which changed between v4.8.0 and v4.9.3.