adjust test workflow to qt6

.github/workflows/Test.yml

@@ -10,18 +10,20 @@ on:
 
 jobs:
   Tests:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     steps:
       - uses: actions/checkout@v1
 
       - name: Install dependencies
         run: |
           sudo apt-get update
-          sudo apt-get install -y libusb-1.0-0-dev qt5-default qt5-qmake qtbase5-dev
+          sudo apt-get install -y libusb-1.0-0-dev qt6-tools-dev qt6-base-dev
+          qtchooser -install qt6 $(which qmake6)
 
       - name: Build Tests
         run: |
           cd Software/PC_Application/LibreVNA-Test
+          export QT_SELECT=qt6
           qmake LibreVNA-Test.pro
           make -j9
         shell: bash