[github] no more submodule

Summary: looks_dead_to_me

Reviewed By: martintrojer

Differential Revision: D24160805

fbshipit-source-id: 2ec42f209

.github/workflows/install.yml

@@ -20,8 +20,6 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v2
-        with:
-          submodules: true
 
       - name: Use OCaml ${{ matrix.ocaml-version }}
         uses: avsm/setup-ocaml@v1