chore: drop dead irpc/irpc-derive workspace deps

irpc 0.16 was declared in the workspace Cargo.toml and consumed by
alknet-call, but no .rs file in the workspace imports it. alknet-call's
wire protocol (src/protocol/wire.rs) is hand-rolled length-prefixed JSON.
The dep was dead weight.

Re-add as 0.17 when alknet-blobs lands (it depends on iroh-blobs 0.103
which pulls irpc 0.17 transitively).

crates/alknet-call/Cargo.toml

@@ -15,7 +15,6 @@ quinn = ["dep:quinn", "dep:rustls", "dep:rustls-native-certs", "dep:rustls-pemfi
 
 [dependencies]
 alknet-core = { path = "../alknet-core" }
-irpc = { workspace = true }
 tokio = { version = "1", features = ["full"] }
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"