CI: Cache wasm-bindgen-cli installation

[Tamschi]

Is your feature request related to a problem? Please describe.

The Browser Test job in the CI workflow takes a very long time due to repeated wasm-bindgen-cli installations.

Describe the solution you'd like

This should be cached somehow.

Describe alternatives you've considered

Maybe there's an Action that could be used here instead?

Additional context

This workflow isn't all that necessary for most of my repositories, aside from making sure the crate at least compiles for Wasm.