Update CI to the latest Vim version

.github/workflows/unittests.yml

@@ -7,7 +7,7 @@ jobs:
     strategy:
       matrix:
         vim:
-          - v8.2.2489
+          - v8.2.4036
           - v8.2.0000
           - v8.1.0000
           - v8.0.0000