nox pip-compile: don't use env to pass nox args

Using env here messes up the quoting for the args passed from the
calling workflows. Now that workflow_dispatch is disabled for the
reusable workflow, it should be safe to use GHA workflow templating
directly.

.github/workflows/reusable-pip-compile.yml

@@ -79,10 +79,9 @@ jobs:
           # Ensure the latest pip version is used
           VIRTUALENV_DOWNLOAD: '1'
           #
-          nox_args: "${{ inputs.nox-args }}"
         run: |
           set -x
-          nox ${nox_args}
+          nox ${{ inputs.nox-args }}
       - name: Push new dependency versions and create a PR
         env:
           GITHUB_TOKEN: ${{ steps.create_token.outputs.token }}