Enforce OP_RETURN standardness #6323

Job	Run time
Check WASM	52s
Check no_std	39s
Build and test (stable, true, --no-default-features --features miniscript/no-std)	2m 6s
Build and test (stable, true, --all-features)	4m 2s
prepare	8s
Build & Test Examples (example_cli)	22s
Build and test (1.63.0, --no-default-features --features miniscript/no-std)	3m 42s
Rust fmt	6s
Build & Test Examples (example_bitcoind_rpc_polling)	29s
Build and test (1.63.0, --all-features)	5m 55s
Build & Test Examples (example_electrum)	43s
Build & Test Examples (example_esplora)	53s
Build & Test Examples (example_wallet_electrum)	45s
Build & Test Examples (example_wallet_esplora_async)	1m 1s
Build & Test Examples (example_wallet_esplora_blocking)	51s
Build & Test Examples (example_wallet_rpc)	33s
clippy_check	1m 9s
	24m 16s

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