Build: Bump Qt6 from 6.6.1 to 6.6.3 (Automated PR)

[github-actions]

This automated Pull Request updates the used Qt6 version to version 6.6.3.

This PR was opened by the workflow Bump dependencies (create-prs)

CHANGELOG: Build: Updated bundled Qt6 to version 6.6.3

[softins]

This Qt version update only affects the main Mac build and the Windows build. I can't test the Mac one, but the Windows build seems to install and run fine, so happy to approve.

[pljones]

I've been building Linux with Qt6 for a while -- we should migrate that, too, fairly soon as it seems stable.

[pljones]

As a general point, though, when I run MaintenanceTool on Linux, 6.6.2 isn't offered. I can see only 6.6.1 and 6.6.3, so I don't know if 6.6.2 is worth updating to?

[softins]

As a general point, though, when I run MaintenanceTool on Linux, 6.6.2 isn't offered. I can see only 6.6.1 and 6.6.3, so I don't know if 6.6.2 is worth updating to?

Looks like 6.6.3 was released in the last couple of days, and the tests in the Bump Dependencies workflow would now return 6.6.3 (I've tested manually). So I'll make the workflow run again, and it should replace this PR with a fresh one.

[github-actions]

PR has been updated for version 6.6.3 by the workflow Bump dependencies (create-prs).

[softins]

So I'll make the workflow run again, and it should replace this PR with a fresh one.

It's even cleverer: it's updated this PR. Will let the CI build and try the Windows version.

[ann0see]

Seems good on macOS 14.4 (Intel)

[softins]

Windows build runs fine.