config(github/reusable-update-flake-lock): Add outputs for the workflow_call

Author: MartinNikov

.github/workflows/reusable-update-flake-lock.yml

@@ -14,6 +14,9 @@ on:
         default: ''
         required: false
         type: string
+    outputs:
+      pr-url: ${{ steps.create-pr.outputs.pull-request-url }}
+      pr-number: ${{ steps.create-pr.outputs.pull-request-number }}
 
     secrets:
       NIX_GITHUB_TOKEN:
@@ -32,8 +35,6 @@ on:
 jobs:
   main:
     runs-on: ${{ fromJSON(inputs.runner) }}
-    outputs:
-      pr_number: ${{ steps.create.outputs.pr_number }}
 
     steps:
       - uses: actions/checkout@v4