wip: what's in /mingw64

Author: flavorjones

.github/workflows/ci.yml

@@ -87,6 +87,8 @@ jobs:
           apt-get: libsqlite3-dev
           mingw: sqlite3
           vcpkg: sqlite3
+      - if: matrix.os == "windows"
+        run: find /mingw64 -name '*dlfcn'
       - if: matrix.syslib == 'disable'
         uses: actions/cache@v4
         with: