Wasmtime 37 claims to support exception handling (hidden behind a flag)

[torokati44]

See: https://github.com/bytecodealliance/wasmtime/releases/tag/v37.0.0 and bytecodealliance/wasmtime#11326.

The flag to enable it is -W exceptions=y - or --wasm=exceptions to be consistent with what's already on the website.