feat(wasm-builder): add support for new `wasm32v1-none` target (#7008)

# Description

Resolves #5777

Previously `wasm-builder` used hacks such as `-Zbuild-std` (required
`rust-src` component) and `RUSTC_BOOTSTRAP=1` to build WASM runtime
without WASM features: `sign-ext`, `multivalue` and `reference-types`,
but since Rust 1.84 (will be stable on 9 January, 2025) the situation
has improved as there is new
[`wasm32v1-none`](https://doc.rust-lang.org/beta/rustc/platform-support/wasm32v1-none.html)
target that disables all "post-MVP" WASM features except
`mutable-globals`.

Previously, your `rust-toolchain.toml` looked like this:

```toml
[toolchain]
channel = "stable"
components = ["rust-src"]
targets = ["wasm32-unknown-unknown"]
profile = "default"
```

It should now be updated to something like this:

```toml
[toolchain]
channel = "stable"
targets = ["wasm32v1-none"]
profile = "default"
```

To build the runtime:

```bash
cargo build --package minimal-template-runtime --release
```

## Integration

If you...