Fix docs pipeline for forks

.github/workflows/docs.yaml

@@ -2,7 +2,7 @@
 name: "Documentation"
 
 on:
-    pull_request:
+    pull_request_target:
         branches:
             - "[0-9]+.[0-9]+"
             - "[0-9]+.x"
@@ -30,6 +30,9 @@ jobs:
         steps:
             - name: "Checkout code"
               uses: "actions/checkout@v4"
+              with:
+                ref: ${{ github.event.pull_request.head.ref }}
+                repository: ${{ github.event.pull_request.head.repo.full_name }}
 
             - name: "Checkout Docs Generator"
               uses: "actions/checkout@v4"