zink: always expose linear float textures

This is not an optional feature in Vulkan, so we can rely on this being
supported. This has the nice benefit of enabling OpenGL ES 3.0 support
on ANV.

Reviewed-by: Hoe Hao Cheng <haochengho12907@gmail.com>
Reviewed-By: Mike Blumenkrantz <michael.blumenkrantz@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8640>

src/gallium/drivers/zink/zink_screen.c

@@ -291,11 +291,9 @@ zink_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
       return 1;
 #endif
 
-#if 0 /* TODO: Enable me */
    case PIPE_CAP_TEXTURE_FLOAT_LINEAR:
    case PIPE_CAP_TEXTURE_HALF_FLOAT_LINEAR:
       return 1;
-#endif
 
    case PIPE_CAP_SHAREABLE_SHADERS:
       return 1;