sdk/js: Add deprecated warning to README #13223

Job	Run time
algorand	7m 7s
ethereum	57s
node	2m 53s
Aptos	3m 9s
cli	2m 30s
cosmwasm	1m 48s
ethereum-upgrade	4m 29s
relayer-ethereum	1m 16s
solana	5m 48s
sdk_vaa	1m 17s
Sui	2m 29s
terra	6m 45s
terra-2	9m 58s
wormchain	4m 47s
docker	7s
npm-packages	4s
prettier	14s
rust-lint-and-tests (cosmwasm/Cargo.toml)	2m 25s
spellcheck	13s
rust-lint-and-tests (terra/Cargo.toml)	1m 37s
rust-lint-and-tests (sdk/rust/Cargo.toml)	34s
tilt	16m 5s
node-lint	21s
node-tests	26s
	1h 17m 19s

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