Regression from
04f9db5b22
Originally I thought to fix the issue in the PR we needed to explicitly
pass through the `node-modules-dir` flag, but after applying the correct
fix that david pointed out (setting `NPM_PROCESS_STATE`) that wasn't
necessary (or correct).
We had a test for deno task with BYONM, but it only tested with
`"unstable": ["byonm"]` in deno.json, so it didn't catch this.