radv: do not remove the PointSize built-in for polygon mode as points

radv: do not remove the PointSize built-in for polygon mode as points

Determine if it can be removed when generating the graphics pipeline
key because of dynamic states.

Fixes new CTS dEQP-VK.rasterization.polygon_as_large_points.* and also
spec@!opengl 1.1@polygon-offset with Zink/RADV.

Cc: 22.3 mesa-stable
Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20073>
(cherry picked from commit b4f940913d386bad0e25a1e224d0f39631124593)