fix wasi-nn and wasi-crypto integrations for wasmtime-wiggle changes

the Rc<RefCell<ctx>> wrapping inside the wasmtime-generated bindings
was eliminated, and instead the caller of ::new(linker, ctx) is
required to wrap the ctx in Rc<RefCell<>>.

The Rc wrapping inside WasiCryptoCtx can be eliminated due to this
change.

crates/wasi-crypto/src/wiggle_interfaces/mod.rs

@@ -1,6 +1,6 @@
 use std::rc::Rc;
 
-use wasi_crypto::CryptoCtx;
+pub use wasi_crypto::CryptoCtx as WasiCryptoCtx;
 
 wiggle::from_witx!({
     witx: ["$CARGO_MANIFEST_DIR/spec/witx/wasi_ephemeral_crypto.witx"],
@@ -17,19 +17,6 @@ pub mod wasi_modules {
 
 pub use types as guest_types;
 
-#[derive(Clone)]
-pub struct WasiCryptoCtx {
-    ctx: Rc<CryptoCtx>,
-}
-
-impl WasiCryptoCtx {
-    pub fn new() -> Self {
-        WasiCryptoCtx {
-            ctx: Rc::new(CryptoCtx::new()),
-        }
-    }
-}
-
 mod asymmetric_common;
 mod common;
 mod error;