wasmtime-wasi: remove dependency on trait-variant (bytecodealliance#10020)

this seems to have been added by mistake. There is a dep on this crate
in wasmtime for use by the component macro, but all use sites use it
through the wasmtime crate's re-export.

Author: pchickey

Cargo.lock

@@ -32,7 +32,6 @@ io-lifetimes = { workspace = true }
 fs-set-times = { workspace = true }
 bitflags = { workspace = true }
 async-trait = { workspace = true }
-trait-variant = {workspace = true}
 system-interface = { workspace = true}
 futures = { workspace = true }
 url = { workspace = true }