Remove subxt (#460)

* Remove subxt

Removes ~20 crates from our Cargo.lock.

Removes downloading the metadata and enables removing the getMetadata RPC route
(relevant to #379).

Moves forward #337.

Done now due to distinctions in the subxt 0.32 API surface which make it
justifiable to not update.

* fmt, update due to deny triggering on a yanked crate

* Correct the handling of substrate_block_notifier now that it's ephemeral, not long-lived

* Correct URL in tests/coordinator from ws to http

substrate/client/Cargo.toml

@@ -17,17 +17,15 @@ rustdoc-args = ["--cfg", "docsrs"]
 zeroize = "^1.5"
 thiserror = { version = "1", optional = true }
 
-futures = "0.3"
-
 hex = "0.4"
 scale = { package = "parity-scale-codec", version = "3" }
-scale-info = { version = "2", optional = true }
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
 
 sp-core = { git = "https://github.com/serai-dex/substrate" }
 sp-runtime = { git = "https://github.com/serai-dex/substrate" }
 serai-runtime = { path = "../runtime", version = "0.1" }
-
-subxt = { version = "0.29", default-features = false, features = ["jsonrpsee-ws"], optional = true }
+simple-request = { path = "../../common/request", version = "0.1" }
 
 bitcoin = { version = "0.31", optional = true }
 
@@ -50,7 +48,7 @@ dockertest = "0.4"
 serai-docker-tests = { path = "../../tests/docker" }
 
 [features]
-serai = ["thiserror", "scale-info", "subxt"]
+serai = ["thiserror"]
 
 networks = []
 bitcoin = ["networks", "dep:bitcoin"]