As reported in issue conan-io#22654, qt depends on freetype/2.13.2 wh…

…ich depends on libpng/1.6.42 which conflicts with qt's dependency on libpng/1.6.40. Bumping the libpng dependency version on libpng

recipes/qt/6.x.x/conanfile.py

@@ -336,7 +336,7 @@ def requirements(self):
             else:
                 self.requires("libjpeg/9e")
         if self.options.get_safe("with_libpng", False) and not self.options.multiconfiguration:
-            self.requires("libpng/1.6.40")
+            self.requires("libpng/1.6.42")
         if self.options.with_sqlite3 and not self.options.multiconfiguration:
             self.requires("sqlite3/3.45.0")
         if self.options.get_safe("with_mysql", False):