Only make contrib nightly CI fallible.

Author: SergioBenitez

.github/workflows/ci.yml

@@ -26,7 +26,6 @@ jobs:
         include:
           - platform: { name: Linux, distro: ubuntu-latest, toolchain: nightly }
             test: { name: Core, flag: "--core" }
-            fallible: true
           - platform: { name: Linux, distro: ubuntu-latest, toolchain: stable }
             test: { name: Release, flag: "--release" }
           - platform: { name: Linux, distro: ubuntu-latest, toolchain: stable }
@@ -35,8 +34,12 @@ jobs:
           - platform: { name: Linux, distro: ubuntu-latest, toolchain: nightly }
             test: { name: UI, flag: "--ui" }
             fallible: true
+          - platform: { name: Linux, distro: ubuntu-latest, toolchain: nightly }
+            test: { name: Contrib, flag: "--contrib" }
+            fallible: true
           - platform: { name: Windows }
-            working-directory: "C:\\a\\${{ github.event.repository.name }}\\${{ github.event.repository.name }}"
+            working-directory:
+              "C:\\a\\${{ github.event.repository.name }}\\${{ github.event.repository.name }}"
 
     steps:
       - name: Checkout Sources