CI: rm submodule checkouts

Seems like HLS does not plan to use submodules.

Author: Anton-Latukha

.github/workflows/bench.yml

@@ -36,8 +36,6 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
-      with:
-        submodules: true
 
     - run: git fetch origin master # check the master branch for benchmarking
 

.github/workflows/build.yml

@@ -27,8 +27,7 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
-      with:
-        submodules: true
+
     - uses: haskell/actions/setup@v1
       with:
         ghc-version  : ${{ matrix.ghc   }}
@@ -164,8 +163,6 @@ jobs:
 
     steps:
       - uses: actions/checkout@v2
-        with:
-          submodules: true
 
       - name: Create source tarball
         run: |

.github/workflows/caching.yml

@@ -67,8 +67,6 @@ jobs:
 
     steps:
       - uses: actions/checkout@v2
-        with:
-          submodules: true
 
       - uses: haskell/actions/setup@v1
         with:

.github/workflows/hackage.yml

@@ -47,8 +47,6 @@ jobs:
     steps:
 
       - uses: actions/checkout@v2
-        with:
-          submodules: true
 
       - uses: haskell/actions/setup@v1
         with:

.github/workflows/nix.yml

@@ -44,8 +44,7 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
-      with:
-        submodules: true
+
     - uses: cachix/install-nix-action@v16
       with:
         install_url: https://nixos-nix-install-tests.cachix.org/serve/i6laym9jw3wg9mw6ncyrk6gjx4l34vvx/install
@@ -79,8 +78,7 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
-      with:
-        submodules: true
+
     - uses: cachix/install-nix-action@v16
       with:
         install_url: https://nixos-nix-install-tests.cachix.org/serve/i6laym9jw3wg9mw6ncyrk6gjx4l34vvx/install

.github/workflows/test.yml

@@ -74,8 +74,6 @@ jobs:
 
     steps:
       - uses: actions/checkout@v2
-        with:
-          submodules: true
 
       - uses: haskell/actions/setup@v1
         with: