Include 4JLibs as a submodule (#1535)

* feat: 4JLibs as a submodule

* fix: forgot submodule

* fix: actions didn't recurse submodules on checkout

* fix: oops, using old commit

.github/workflows/nightly.yml

@@ -20,6 +20,8 @@ jobs:
     steps:
     - name: Checkout
       uses: actions/checkout@v6
+      with:
+        submodules: recursive
 
     - name: Setup MSVC
       uses: ilammy/msvc-dev-cmd@v1
@@ -95,6 +97,8 @@ jobs:
     steps:
     - name: Checkout
       uses: actions/checkout@v6
+      with:
+        submodules: recursive
 
     - name: Setup MSVC
       uses: ilammy/msvc-dev-cmd@v1