Renovate host example with latest `wasmtime` and `wasmtime_wasi`

[ifsheldon]

https://github.com/bytecodealliance/component-docs/tree/main/component-model/examples/example-host

This example is pretty outdated, as it uses wasmtime and wasmtime_wasi of version 18.0 but the latest is 27.0. I can try to make a PR to renovate that.

[kate-goldenring]

That would be great @ifsheldon