CI: update packages on Linux

Author: HuguesDelorme

.github/workflows/ci_linux_ubuntu.yml

@@ -18,6 +18,7 @@ jobs:
 
         - name: Install Qt${{matrix.qt_version_major}}
           run: |
+              sudo apt-get -y update
               if [[ ${{matrix.qt_version_major}} == "5" ]]; then
                   sudo apt-get -y install qtbase5-dev libqt5svg5-dev
               elif [[ ${{matrix.qt_version_major}} == "6" ]]; then