Parameter expansion doesn't appear to work in `publish` command

[steveluscher]

I have the following config:

      - name: Create Changesets Pull Request or Publish to NPM
        id: changesets
        uses: changesets/action@v1
        with:
          publish: pnpm turbo publish-packages --concurrency=${TURBO_CONCURRENCY:-1}
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
          PUBLISH_TAG: next

The ${TURBO_CONCURRENCY:-1} parameter expansion does not seem to work. I received the error:

/home/runner/setup-pnpm/node_modules/.bin/pnpm turbo publish-packages --concurrency=${TURBO_CONCURRENCY:-1}
  x Invalid value for `--concurrency` flag. This should be a positive integer
  | greater than or equal to 1: ${TURBO_CONCURRENCY:-1}

I believe this must be because --concurrency was passed the literal value ${TURBO_CONCURRENCY:-1} instead of the result of the parameter expansion (ie. 1).