Stabilize V16 metadata

[jsdw]

This PR bumps frame-metadata 23.0.0, which stabilizes V16 metadata. This was previously available as the "unstable" metadata.

The main additions provided by V16 metadata are:

• Information about the Pallet View Functions exposed by pallets.
• Information about the Config associated types used by each pallet.
• Support for V5 transactions, including support for a chain providing multiple transaction extension versions and multiple supported transaciton versions.
• Support for deprecation information, so that mostly anything defined in a runtime can be marked as deprecated in order for runtime/pallet authors to communicate to consumers about deprecated items.

To sanity check this, I've built a polkadot node with this change and checked that using Subxt (this PR paritytech/subxt#1999), v16 metadata is indeed available, downloads and decodes correctly.

[jsdw]

@bkchr Do you think we should update merkleized-metadata to support frame-metadata@23(which contains the now-stabilized V16 metadata) and then release it prior to merging this PR or after? Given your looser version constraints there we can do things either way around I think!

One constraint is that I'd like to get this merged before the release cutoff date on May 15th to get it into the next stable release, so my preference is to merge this first and update that later.

[bkchr]

@bkchr Do you think we should update merkleized-metadata to support frame-metadata@23(which contains the now-stabilized V16 metadata) and then release it prior to merging this PR or after? Given your looser version constraints there we can do things either way around I think!

Given the looser version requirements, no change to merkleized-metadata should be required.

[jsdw]

Given the looser version requirements, no change to merkleized-metadata should be required.

Makes sense! I guess it will eventually want to be updated for V16 metadata so that it can be used for decoding/checking v5 transactions (because V16 metadata contains the transaction extensions for each possible version the extrinsic might use)?

[paritytech-workflow-stopper]

All GitHub workflows were cancelled due to failure one of the required jobs.
Failed workflow url: https://github.com/paritytech/polkadot-sdk/actions/runs/14904466681
Failed job name: test-linux-stable