CI: install taplo from pre-built binary instead of source

[dannywillems]

Description

`.github/workflows/ci.yml:78` installs taplo by compiling from source:

```yaml

• name: Install taplo
  run: cargo install taplo-cli
  ```

This is slow. Should use pre-built binaries (e.g., `tamasfe/taplo-action` or download from GitHub releases) to speed up CI.