Enable new WIT encoding by default

This commit enables the new encoding for WIT packages in WebAssembly
components described in WebAssembly/component-model#248 and originally
implemented in bytecodealliance#1252. Support for the new encoding has been in a
wasm-tools for a bit and it's also released with Wasmtime 14. This
switch means that infrastructure will start being exposed to it by
default now. Support for the old encoding remains to assist with interop
as well. In a release or two support for creating the old encoding will
be removed.

crates/wit-component/src/encoding/wit/mod.rs

@@ -5,7 +5,7 @@ use wit_parser::{PackageId, Resolve, WorldId};
 mod v1;
 mod v2;
 
-const ENCODE_V2_BY_DEFAULT: bool = false;
+const ENCODE_V2_BY_DEFAULT: bool = true;
 
 fn use_v2_encoding() -> bool {
     match std::env::var("WIT_COMPONENT_ENCODING_V2") {