actions: fix template

Signed-off-by: lucasew <lucas59356@gmail.com>

Author: lucasew

.github/workflows/nixpkgs-review.yml

@@ -1,7 +1,7 @@
 # This is a basic workflow to help you get started with Actions
 
 name: nixpkgs-review a nixpkgs PR
-run-name: 'nixpkgs-review #${{ github.inputs.pr }}'
+run-name: 'nixpkgs-review #${{ github.events.inputs.pr }}'
 
 # Controls when the action will run. Triggers the workflow on push or pull request
 # events but only for the master branch