fix: print origin pr url to dest pr body

(cherry picked from commit 632b77ff09)

.forgejo/workflows/integration.yml

@@ -4,6 +4,7 @@ on:
   push:
     branches:
       - 'main'
+      - 'v*'
   pull_request:
 
 jobs:

cascading-pr.sh

@@ -81,7 +81,11 @@ function pr_destination_title() {
 }
 
 function pr_destination_body() {
-    echo "cascading-pr from ${options[origin_url]}/${options[origin_repo]} ${options[origin_head]}"
+    if [[ -n "${options[origin_pr]}" ]]; then
+        echo "cascading-pr from ${options[origin_url]}/${options[origin_repo]}/pulls/${options[origin_pr]}"
+    else
+        echo "cascading-pr from ${options[origin_url]}/${options[origin_repo]} ${options[origin_head]}"
+    fi
 }
 
 function upsert_destination_pr() {