Ensure submodules are checked out in ci

Author: martijn-resolume

.github/workflows/macos.yml

@@ -13,6 +13,8 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
+      with:
+        submodules: recursive
     - name: cmake
       run: cmake -B build -DCMAKE_BUILD_TYPE=Debug
     - name: build

.github/workflows/ubuntu.yml

@@ -13,6 +13,8 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
+      with:
+        submodules: recursive
     - name: compiler
       run: sudo apt-get update && sudo apt-get install -y clang
     - name: cmake

.github/workflows/windows.yml

@@ -13,6 +13,8 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
+      with:
+        submodules: recursive
     - name: cmake
       run: cmake -B build -DCMAKE_BUILD_TYPE=Debug -DCMAKE_CXX_COMPILER=/usr/bin/clang++
     - name: build