v0.24.0

This release has a bunch of smaller changes and fixes. The breaking changes are fairly minor and should be easy to address if encountered. Notable additions are:

• Allowing the underlying RPC implementation to be swapped out (#634). This makes jsonrpsee an optional dependency, and opens the door for Subxt to be integrated into things like light clients, since we can decide how to handle RPC calls.
• A low level "runtime upgrade" API is exposed, giving more visibility into when node updates happen in case your application needs to handle them.
• scale-value and scale-decode dependencies are bumped. The main effect of this is that bitvec is no longer used under the hood in the core of Subxt, which helps to remove one hurdle on the way to being able to compile it to WASM.

Notable PRs merged:

Added

• feat: add low-level runtime upgrade API (#657)
• Add accessor for StaticTxPayload::call_data (#660)
• Store type name of a field in event metadata, and export EventFieldMetadata (#656 and #654)
• Allow generalising over RPC implementation (#634)
• Add conversion and default functions for NumberOrHex (#636)
• Allow creating/submitting unsigned transactions, too. (#625)
• Add Staking Miner and Introspector to usage list (#647)

Changed

• Bump scale-value and scale-decode (#659)
• Tweak 0.23 notes and add another test for events (#618)
• Specialize metadata errors (#633)
• Simplify the TxPayload trait a little (#638)
• Remove unnecessary async (#645)
• Use 'sp_core::Hxxx' for all hash types (#623)

Fixed

• Fix history_depth testing (#662)
• Fix codegen for codec::Compact as type parameters (#651)
• Support latest substrate release (#653)