GitHub CI Win: install windeployqt for Qt6

.github/scripts/Windows/prepare_msys.sh

@@ -1,6 +1,4 @@
-#!/bin/bash
-
-set -ex
+#!/bin/sh -eux
 
 mkdir -p /usr/local/lib /usr/local/bin /usr/local/include
 cat >> ~/.bash_profile <<'EOF'
@@ -46,7 +44,7 @@ $PACMAN_INSTALL ${MSYS_REPO}-glew ${MSYS_REPO}-SDL2 ${MSYS_REPO}-freeglut
 $PACMAN_INSTALL ${MSYS_REPO}-portaudio # in case of problems build PA with --with-winapi=wmme,directx,wasapi
 $PACMAN_INSTALL ${MSYS_REPO}-glib2 ${MSYS_REPO}-curl # RTSP capture
 pacman -Scc --noconfirm # make some free space
-$PACMAN_INSTALL ${MSYS_REPO}-qt6-base
+$PACMAN_INSTALL ${MSYS_REPO}-qt6-base ${MSYS_REPO}-qt6-tools
 $PACMAN_INSTALL ${MSYS_REPO}-imagemagick ${MSYS_REPO}-opencv
 $PACMAN_INSTALL p7zip
 $PACMAN_INSTALL libtool # PCP

.github/workflows/ccpp.yml

@@ -309,7 +309,7 @@ jobs:
           export DESTDIR=build/UltraGrid-$VERSION-win64
           make install
           IFS=\"|\"; for exe in $DESTDIR/*exe; do for n in `data/scripts/get_dll_depends.sh \"$exe\" | tr \"\n\" \"|\"`; do cp \"$n\" $DESTDIR; done; done
-          windeployqt $DESTDIR/uv-qt.exe
+          if $(command -v windeployqt-qt6 >/dev/null); then windeployqt-qt6 $DESTDIR/uv-qt.exe; else windeployqt $DESTDIR/uv-qt.exe; fi
           cp data/update.ps1 $DESTDIR'
     - name: make dist-check
       run: C:\msys64\usr\bin\bash -cel 'PATH=