MAINT: Need to be explicit with action path while using pixi run too (#98)

* Provide '--manifest-path' option to 'pixi run' to ensure the environment is properly activated.

      --manifest-path <MANIFEST_PATH>
          The path to 'pixi.toml' or 'pyproject.toml'

Author: MridulS

action.yml

@@ -45,4 +45,4 @@ runs:
         INPUT_ANACONDA_NIGHTLY_UPLOAD_TOKEN: ${{ inputs.anaconda_nightly_upload_token }}
         INPUT_ANACONDA_NIGHTLY_UPLOAD_LABELS: ${{ inputs.anaconda_nightly_upload_labels }}
       run: |
-        pixi run ${{ github.action_path }}/upload_wheels.sh
+        pixi run --manifest-path ${{ github.action_path }}/pixi.toml ${{ github.action_path }}/upload_wheels.sh