build.yaml: Cover Qt 6 on ubuntu-22.04 as well

Author: hartwork

.github/workflows/build.yaml

@@ -41,6 +41,10 @@ jobs:
             qt_major: 5
             qt_qmake: qmake
             qt_packages: qt5-qmake qtbase5-dev
+          - runs-on: ubuntu-22.04
+            qt_major: 6
+            qt_qmake: qmake6
+            qt_packages: qmake6 qt6-base-dev libqt6core5compat6-dev
           - runs-on: ubuntu-22.04
             qt_major: 5
             qt_qmake: qmake