Downgrade requirements for WASM dependencies

[djc]

WebAssembly support was added in #38 targeting the current versions versions of wasm-bindgen and js-sys at the time, which is reasonable. Unfortunately the whoami crate, in trying to support older Rust versions, has reduced the upper version of wasm-bindgen that it supports, see ardaku/whoami#43.

This PR thus reduces the minimum version required for wasm-bindgen. I used cargo +nightly update -Z minimal-versions with cargo build --target wasm32-unknown-unknown to find the earliest version that compiles. We could theoretically set up checks in CI to verify this on an ongoing basis, but this might be overkill for now.

cc @Kijewski

[astraw]

Rolling back the versions in Cargo.toml seems reasonable to me if you tested things work with those versions. I'm +1. @Kijewski what do you think?

(Adding CI tests to prove that the minimum package versions specified in Cargo.toml do function is a good idea - for all crates - but IMO not necessary at this stage. I haven't seen an implementation of such, nor have I looked.)

[djc]

Rolling back the versions in Cargo.toml seems reasonable to me if you tested things work with those versions.

Note that I only compile-tested one target (as mentioned in the description), I'm not normally a WASM user and running the tests against a WASM target didn't seem to work.

(Adding CI tests to prove that the minimum package versions specified in Cargo.toml do function is a good idea - for all crates - but IMO not necessary at this stage. I haven't seen an implementation of such, nor have I looked.)

I think a number of crates (like Tokio) have started to exercise cargo update -Z minimal-versions in CI, but there are still a number of pain points to be ironed out (which is why Cargo hasn't stabilized minimal-versions yet).

[Kijewski]

Thank you! The PR looks good to me, and I'll try it this evening.

It is possible to use -Zminimal-versions in stable, and also quite old versions: ci.yml. The documentation for RUSTC_BOOTSTRAP is a bit hidden, and you are not supposed to use it, but it works perfectly fine for use cases like this.

[astraw]

This is published in release 0.1.48.