disabled installation of Qt dependencies in CI when we only require the headers (danmar#7214)

Author: firewave

.github/workflows/clang-tidy.yml

@@ -33,8 +33,7 @@ jobs:
           sudo apt-get update
           sudo apt-get install -y cmake make
           sudo apt-get install -y libpcre3-dev
-          sudo apt-get install -y libffi7 # work around missing dependency for Qt install step
-          sudo apt-get install -y libcups2-dev  # required for Qt6PrintSupport in CMake since Qt 6.7.3
+          sudo apt-get install -y libgl-dev  # fixes missing dependency for Qt in CMake
 
       - name: Install clang
         run: |
@@ -49,6 +48,7 @@ jobs:
         with:
           version: ${{ env.QT_VERSION }}
           modules: 'qtcharts'
+          install-deps: false
           cache: true
 
       - name: Verify clang-tidy configuration

.github/workflows/iwyu.yml

@@ -44,7 +44,6 @@ jobs:
           apt-get update
           apt-get install -y cmake clang make libpcre3-dev
           apt-get install -y libgl-dev  # fixes missing dependency for Qt in CMake
-          apt-get install -y libcups2-dev  # required for Qt6PrintSupport in CMake since Qt 6.7.3
           apt-get install -y iwyu
 
       - name: Install missing software on archlinux
@@ -70,7 +69,6 @@ jobs:
           dnf install -y cmake clang pcre-devel
           dnf install -y libglvnd-devel  # fixes missing dependency for Qt in CMake
           dnf install -y p7zip-plugins  # required as fallback for py7zr in Qt installation
-          dnf install -y cups-devel  # required for Qt6PrintSupport in CMake since Qt 6.7.3
           dnf install -y iwyu
           ln -s iwyu_tool.py /usr/bin/iwyu_tool
 
@@ -167,7 +165,6 @@ jobs:
         run: |
           sudo apt-get update
           sudo apt-get install -y cmake make libpcre3-dev
-          sudo apt-get install -y libcups2-dev  # required for Qt6PrintSupport in CMake since Qt 6.7.3
           sudo apt-get install -y libgl-dev  # missing dependency for using Qt in CMake
 
       - name: Install clang

.github/workflows/selfcheck.yml

@@ -39,13 +39,14 @@ jobs:
           sudo apt-get install clang-14
           sudo apt-get install libboost-container-dev
           sudo apt-get install valgrind
-          sudo apt-get install -y libcups2-dev  # required for Qt6PrintSupport in CMake since Qt 6.7.3
+          sudo apt-get install -y libgl-dev  # fixes missing dependency for Qt in CMake
 
       - name: Install Qt ${{ env.QT_VERSION }}
         uses: jurplel/install-qt-action@v4
         with:
           version: ${{ env.QT_VERSION }}
           modules: 'qtcharts'
+          install-deps: false
           cache: true
 
       # TODO: cache this - perform same build as for the other self check