### Godot version

4.0.2.stable

### System information

Windows 11, Vulkan, RTX2070 Super

### Issue description

Reading from `VIEWPORT_SIZE` in the `light()` function causes spatial shader to break and renders as default white.

### Steps to reproduce

![image](https://user-images.githubusercontent.com/20043270/236914345-ccd12e83-4431-4a53-b67b-028c8ef5719b.png)

when line 51 is present the fails to compile with the following message in the output log but no compilation errors.

```
servers/rendering/renderer_rd/forward_clustered/scene_shader_forward_clustered.cpp:171 - Condition "!shader_singleton->shader.version_is_valid(version)" is true.
  drivers/vulkan/rendering_device_vulkan.cpp:5361 - Condition "!shader" is true. Returning: RID()
  drivers/vulkan/rendering_device_vulkan.cpp:5835 - Condition "!us" is true.
```

commenting out line 51 solves this issue.

[The documentation](https://docs.godotengine.org/en/stable/tutorials/shaders/shader_reference/spatial_shader.html#light-built-ins) states that `VIEWPORT_SIZE` should be available to the `light()` function.

### Minimal reproduction project

N/A
actions.renames["COLOR"] = "color_interp";
		actions.renames["POINT_SIZE"] = "gl_PointSize";
		actions.renames["INSTANCE_ID"] = "gl_InstanceIndex";
		actions.renames["VERTEX_ID"] = "gl_VertexIndex";
		actions.renames["ALPHA_SCISSOR_THRESHOLD"] = "alpha_scissor_threshold";
		actions.renames["ALPHA_HASH_SCALE"] = "alpha_hash_scale";
		actions.renames["ALPHA_ANTIALIASING_EDGE"] = "alpha_antialiasing_edge";
		actions.renames["ALPHA_TEXTURE_COORDINATE"] = "alpha_texture_coordinate";
		
		actions.renames["TIME"] = "global_time";
		actions.renames["EXPOSURE"] = "(1.0 / scene_data_block.data.emissive_exposure_normalization)";
		actions.renames["PI"] = _MKSTR(Math_PI);
		actions.renames["TAU"] = _MKSTR(Math_TAU);
		actions.renames["E"] = _MKSTR(Math_E);
		actions.renames["VIEWPORT_SIZE"] = "scene_data.viewport_size";
		actions.renames["FRAGCOORD"] = "gl_FragCoord";
		actions.renames["FRONT_FACING"] = "gl_FrontFacing";
		actions.renames["NORMAL_MAP"] = "normal_map";
		actions.renames["NORMAL_MAP_DEPTH"] = "normal_map_depth";
		actions.renames["ALBEDO"] = "albedo";
		actions.renames["ALPHA"] = "alpha";
		actions.renames["METALLIC"] = "metallic";
		actions.renames["SPECULAR"] = "specular";
		actions.renames["ROUGHNESS"] = "roughness";
		actions.renames["RIM"] = "rim";
		actions.renames["RIM_TINT"] = "rim_tint";
		actions.renames["CLEARCOAT"] = "clearcoat";
		actions.renames["CLEARCOAT_ROUGHNESS"] = "clearcoat_roughness";
		actions.renames["ANISOTROPY"] = "anisotropy";
		actions.renames["ANISOTROPY_FLOW"] = "anisotropy_flow";