Merge pull request #1536 from stan-dev/fix-windows-gha

Fix cross-windows build in Github Actions

Author: WardBrian

.github/workflows/binaries.yml

@@ -99,7 +99,7 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Install cross-compiler
-        run: sudo apt-get update; sudo apt-get install -y gcc-mingw-w64-x86-64
+        run: sudo apt-get update; sudo apt-get install -y gcc-mingw-w64-x86-64 gcc-mingw-w64-i686
 
       - name: Use OCaml ${{ env.OCAML_VERSION }}
         uses: ocaml/setup-ocaml@v3