Update windows.yml

Author: raysan5

.github/workflows/windows.yml

@@ -83,7 +83,7 @@ jobs:
         x86_64-w64-mingw32-gcc.exe --version
         windres.exe --version
         dir C:\msys64\mingw64\bin
-        make PLATFORM=PLATFORM_DESKTOP CC=x86_64-w64-mingw32-gcc.exe RAYLIB_LIBTYPE=STATIC RAYLIB_RELEASE_PATH="../build/${{ env.RELEASE_NAME }}/lib" EXTERNAL_CONFIG_FLAGS=-m32
+        make PLATFORM=PLATFORM_DESKTOP CC=x86_64-w64-mingw32-gcc.exe RAYLIB_LIBTYPE=STATIC RAYLIB_RELEASE_PATH="../build/${{ env.RELEASE_NAME }}/lib" CUSTOM_CFLAGS=-m32
         //windres.exe -i raylib.dll.rc -o raylib.dll.rc.data -O coff --target=${{ matrix.WINDRES_ARCH }}
         //make PLATFORM=PLATFORM_DESKTOP CC=${{ matrix.ARCH }}-w64-mingw32-gcc.exe RAYLIB_LIBTYPE=SHARED RAYLIB_RELEASE_PATH="../build/${{ env.RELEASE_NAME }}/lib" -B
         cd ..