zink: add a workaround for a nir_assign_io_var_locations bug

zink: add a workaround for a nir_assign_io_var_locations bug

drivers that use nir_assign_io_var_locations() with EXT_shader_object all
have the same bug with a shader interface that looks like this:

shader output block:
* PSIZ
* VAR0
* VAR8

shader input block:
* VAR0
* VAR8

in this case, output driver locations will be assigned like:
* PSIZ=0
* VAR0=1
* VAR8=2

and input driver locations will be:
* VAR0=0
* VAR8=1

which breaks the shaders even though this is a totally legitimate thing
to do

thus, a second set of shaders have to be created without PSIZ to work around
the bug since I've already spent 18+ hours trying to fix it and have only succeeded
in breaking every driver that uses it

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/22725>