ci: update qt6 branch to node20 based actions

[csett86]

Same as on develop

[what-the-diff[bot]]

Motivational Summary of Changes 🌈⚡️

Let's seize the day folks! 😀 We've done a fantastic job upgrading the version of several actions in our CI workflow, bringing us up-to-date with their latest features. Here's a concise overview of the hearty changes:

• Action Upgraded: actions/checkout 🎉 We've updated this action to version 4 in our CI workflow. More advanced and good to go!

• Action Upgraded: actions/upload-artifact 🚀 Kudos to us, we've updated this action to version 4 in our CI workflow.

• Action Upgraded: jurplel/install-qt-action ⭐ Stepping up the pace, we've updated this action to version 3 in our CI workflow.

• Action Upgraded: actions/download-artifact 💪 Charged up, we've updated this action to version 4 in our CI workflow.

• Action Upgraded: softprops/action-gh-release 🥳 We've sprinted ahead, updating this action to version 2 in our CI workflow.

• Action Upgraded: DenverCoder1/doxygen-github-pages-action 🏃‍♀️ Racing forwards, we've committed 60e8d33d954eafb4d54710db8130fb0ad8f7d157 to update this action in our CI workflow.

These small steps are a leap towards a much smother, efficient, and exciting development process. It's another amazing stride towards greatness: Good job team! Emoji-handle here, emoji-handle there, let's bring more efficiency everywhere! 💫🏄‍♀️🔥