x11-toolkits: update to 1.10.0

• Remove LOCAL mirror (not needed)
• Add git build dependency
• Add missing pygment dependency
• Sort USES section and USE_PYTHON variable
• Indicate that the port supports Python 3 (thus adding FLAVORS)
• Make sphinx dependency versions (i.e. support python 3)
• Add missing dependencies for GSTREAMER option:
  • gettext-runtime
  • glib20
• Add missing dependency for X11 option: render (x11)
• Remove PDF install target, no longer an option
• Remove pkg-plist that is autogenerated (only DOCS remains)
• Change log: https://kivy.org/#changelog

PR: 224734
Submitted by: Christian Sturm <reezer@reezer@org>