add try-catch for get-pr

Author: commit111

.github/workflows/check-sample.yml

@@ -70,7 +70,11 @@ jobs:
                   repo: context.repo.repo,
                   pull_number: pr_number
               });
+            } catch (getPrError) {
+                throw new Error ("Could not get current PR from source. Please fix the issues and try again.")
+            }
 
+            try {
               let newBody;
               const body = pullRequest.body || "";
               const markerIndex = body.indexOf(marker);
@@ -97,7 +101,6 @@ jobs:
             if (error) {
               throw new Error("Incomplete samples checklist. Please fix the issues and try again.");
             }
-            
 
       - name: Create / Update Template Repo
         uses: actions/github-script@v7