fix(gui): Port Deskflow Qt 6.9 fix - #2231

@p12tic This PR should make it in for 3.3.0. It is critical.

@p12tic I took this fix from Deskflow, but the static inline integer in KeySequence.h seems to require C++ STD 17+.

Have you got any other thoughts on how to approach this w/o bumping C++ std on Windows?

Why not just cast it to uint as per the release notes?

The relevant section, if I understand it correctly:

563ed822f86 QString: toward UTF-8 arg() support [3½/4]: port unary arg() to QAnyStringView The QString::arg() overloads have been redesigned. Character-like types (char, char16_t, char8_t, wchar_t (still subject to QTBUG-126054 at the time of writing), char32_t) now always output the character, not its numeric value. In particular, char16_t and char arguments now match the string-ish arg() overload (and therefore don't provide a base argument anymore. A backwards-compatible fix is to cast char, char16_t, and wchar_t arguments to uint. This also fixes the ambiguity errors you may have seen when using a char16_t as fillChar.

I applied this patch to the source and it builds with Qt 6.9.0.

don't use uint use uint16_t so the size is ensured. (uint should be 2bytes but not on all platforms)

Closing in favor of #2232.