### 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["BONE_WEIGHTS"] = "weight_attrib";
		actions.renames["CUSTOM0"] = "custom0_attrib";
		actions.renames["CUSTOM1"] = "custom1_attrib";
		actions.renames["CUSTOM2"] = "custom2_attrib";
		actions.renames["CUSTOM3"] = "custom3_attrib";
		actions.renames["OUTPUT_IS_SRGB"] = "SHADER_IS_SRGB";
		actions.renames["NODE_POSITION_WORLD"] = "read_model_matrix[3].xyz";
		actions.renames["CAMERA_POSITION_WORLD"] = "scene_data.inv_view_matrix[3].xyz";
		actions.renames["CAMERA_DIRECTION_WORLD"] = "scene_data.view_matrix[3].xyz";
		actions.renames["CAMERA_VISIBLE_LAYERS"] = "scene_data.camera_visible_layers";
		actions.renames["NODE_POSITION_VIEW"] = "(scene_data.view_matrix * read_model_matrix)[3].xyz";
		actions.renames["VIEW_INDEX"] = "ViewIndex";
		actions.renames["VIEW_MONO_LEFT"] = "0";
		actions.renames["VIEW_RIGHT"] = "1";
		actions.renames["EYE_OFFSET"] = "eye_offset";
		
		actions.renames["VIEW"] = "view";
		actions.renames["SPECULAR_AMOUNT"] = "specular_amount";
		actions.renames["LIGHT_COLOR"] = "light_color";
		actions.renames["LIGHT_IS_DIRECTIONAL"] = "is_directional";
		actions.renames["LIGHT"] = "light";
		actions.renames["ATTENUATION"] = "attenuation";
		actions.renames["DIFFUSE_LIGHT"] = "diffuse_light";
		actions.renames["SPECULAR_LIGHT"] = "specular_light";
		actions.usage_defines["NORMAL"] = "#define NORMAL_USED\n";
		actions.usage_defines["TANGENT"] = "#define TANGENT_USED\n";
		actions.usage_defines["BINORMAL"] = "@TANGENT";
		actions.usage_defines["RIM"] = "#define LIGHT_RIM_USED\n";
		actions.usage_defines["RIM_TINT"] = "@RIM";
		actions.usage_defines["CLEARCOAT"] = "#define LIGHT_CLEARCOAT_USED\n";