Next release (0.3.0)

After doing the 0.2.x releases here's my things I noted:
- manually have to remember to change version in cargo.toml https://github.com/bitcoindevkit/rust-cktap/commit/c3b271551a5649cf3fa15cd31f3885262a5ee499
- would like to automate this because it could easily be forgotten
- can automate with a `Pre-Release` Github Action workflow
- im good with this, but it would have an automated commit like https://github.com/bitcoindevkit/rust-cktap/commit/5ea29917f5ffe6ae5c648975636d2088778e131e
- not sure if everyone is ok with the automated commits?
- would like to update current release https://github.com/bitcoindevkit/rust-cktap/releases/tag/v0.2.2 workflow to change the text where it currently says `Swift bindings release v0.2.2` to make it something more broad/encompassing of the rust part of things too
- maybe change Github Action workflow name too ("Swift") to not be so specific to swift only (rust here too)