🎁 Update to wasmtime 22.0.0 (fastly#392)

Update to wasmtime 22.0.0.

This included some pretty substantial changes to the wiggle crate, which removes
runtime borrow checking of guest memory. This is a huge ergonomic improvement,
as the borrows are all tracked as rrust borrows instead.

One piece of functionality that's missing after the wiggle changes is the
ability to interact with a slice of guest memory that's not &[u8]. To work
around this, I'm copying memory over to the host, but in future releases of
wiggle we should have the ability to interact with slices that aren't just to
u8.

Cargo.toml

@@ -40,10 +40,10 @@ futures = "0.3.24"
 url = "2.3.1"
 
 # Wasmtime dependencies
-wasmtime = "21.0.0"
-wasmtime-wasi = "21.0.0"
-wasmtime-wasi-nn = "21.0.0"
-wiggle = "21.0.0"
+wasmtime = "22.0.0"
+wasmtime-wasi = "22.0.0"
+wasmtime-wasi-nn = "22.0.0"
+wiggle = "22.0.0"
 wasmparser = "0.208.0"
 wasm-encoder = { version = "0.208.0", features = ["wasmparser"] }
 wit-component = "0.208.0"