fix(CI): fixed kf6 version for appveyor build

Author: BLumia

appveyor.yml

@@ -11,7 +11,7 @@ environment:
     - job_name: mingw_64_qt6_8
       QTDIR: C:\Qt\6.8\mingw_64
       MINGW64: C:\Qt\mingw_64\Tools\mingw1310_64
-      KF_BRANCH: master
+      KF_BRANCH: v6.24.0
       EXIV2_VERSION: "0.28.7"
       EXIV2_CMAKE_OPTIONS: "-DEXIV2_ENABLE_BROTLI=OFF -DEXIV2_ENABLE_INIH=OFF -DEXIV2_BUILD_EXIV2_COMMAND=OFF"
       PPIC_CMAKE_OPTIONS: "-DPREFER_QT_5=OFF"