Remove window hints clearing the flag Qt::WindowContextHelpButtonHint,
which is already off by default in Qt 6.

In Qt 5 this flag was set by default for QDialogs, and on Windows put a
? button in the corner of the title bar allowing users to activate Qt's
QWhatsThis help system for a given widget. Since we don't set that text
the ? button was useless and so we hid it manually.

The player getting a better view of their surroundings than the game would normally allow could possibly give the player an advantage over the original hardware, so Freelook is disabled in hardcore mode. To do this, I disable the config flag for Freelook when it is accessed, to make sure that it is disabled whether it was enabled before or after hardcore mode was enabled.

SPDX standardizes how source code conveys its copyright and licensing
information. See https://spdx.github.io/spdx-spec/1-rationale/ . SPDX
tags are adopted in many large projects, including things like the Linux
kernel.