fix: support for --jitless

When running Node with `--jitless`, WebAssembly is unavailable. I have a (weird) benchmark-related use-case for it, but because of `es-module-lexer` it is currently not working. This PR makes the WebAssembly lexer import gated behind a check, so it gracefully falls back to the plain js implementation in this scenario. I also tucked in a workaround for an issue with node-gyp and node-pty, as well as upgrading pnpm. 😄