fix output file name

Author: yogh333

.github/workflows/nightly_build_and_test.yml

@@ -31,7 +31,7 @@ jobs:
           id: get_rust_apps
           run: |
             python .github/workflows/get_rust_app_branch.py ${{ secrets.GITHUB_TOKEN }}
-            echo "rust_apps=$(cat rust_apps.json)" >> $GITHUB_OUTPUT
+            echo "rust_apps=$(cat rust_app_branch.json)" >> $GITHUB_OUTPUT
 
     display-rust-apps:
       name: Display Rust Apps