fix windows workflow

.github/workflows/build-windows.yml

@@ -121,14 +121,14 @@ jobs:
           git clone https://github.com/lxqt/lxqt-build-tools.git
           pushd lxqt-build-tools
           mkdir build && cd build
-          cmake ..
+          cmake .. -DCMAKE_PREFIX_PATH="$Qt6_DIR"
           make install
           popd
 
           git clone https://github.com/uncor3/qtermwidget.git
           pushd qtermwidget
           mkdir build && cd build
-          cmake ..
+          cmake .. -DCMAKE_PREFIX_PATH="$Qt6_DIR"
           make install
           popd
 
@@ -177,7 +177,7 @@ jobs:
 
       - name: Configure CMake
         run: |
-          cmake -B build -S . -DCMAKE_BUILD_TYPE=Release
+          cmake -B build -S . -DCMAKE_BUILD_TYPE=Release -DCMAKE_PREFIX_PATH="$Qt6_DIR"
 
       - name: Build with CMake
         run: cmake --build build --config Release