Backport/2412: Expose the unstable metadata v16 #6971

Job	Run time
preflight / preflight	1m 17s
preflight / ci-versions	1m 4s
test-full-crypto-feature	2m 45s
cargo-check-benches (master)	21m 23s
test-frame-ui	47m 2s
cargo-check-benches (current)	24m 31s
test-node-metrics	11m 11s
cargo-check-each-crate (1)	20m 59s
cargo-check-each-crate (2)	24m 54s
cargo-check-each-crate (3)	9m 55s
cargo-check-all-crate-macos	11m 18s
cargo-check-each-crate (4)	22m 48s
cargo-check-each-crate (5)	31m 19s
cargo-check-each-crate (6)	15m 45s
cargo-check-each-crate (7)	34m 48s
test-frame-examples-compile-to-wasm	3m 21s
check-tracing	2m 32s
test-deterministic-wasm	6m 22s
node-bench-regression-guard	17s
check-metadata-hash	6m 14s
All test misc tests passed	1s
	4h 59m 46s

Provide feedback