### 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
}
			shader_versions.push_back(version);
		}
		shader.initialize(shader_versions, p_defines);
		if (!RendererCompositorRD::get_singleton()->is_xr_enabled()) {
			shader.set_variant_enabled(SHADER_VERSION_DEPTH_PASS_MULTIVIEW, false);
			shader.set_variant_enabled(SHADER_VERSION_DEPTH_PASS_WITH_NORMAL_AND_ROUGHNESS_MULTIVIEW, false);
			shader.set_variant_enabled(SHADER_VERSION_DEPTH_PASS_WITH_NORMAL_AND_ROUGHNESS_AND_VOXEL_GI_MULTIVIEW, false);
			
			for (int i = 0; i < SHADER_COLOR_PASS_FLAG_COUNT; i++) {
				
				if ((i & SHADER_COLOR_PASS_FLAG_MULTIVIEW)) {
					shader.set_variant_enabled(i + SHADER_VERSION_COLOR_PASS, false);
				}
			}
		}
	}
	valid_color_pass_pipelines.insert(0);
	valid_color_pass_pipelines.insert(PIPELINE_COLOR_PASS_FLAG_TRANSPARENT);
	valid_color_pass_pipelines.insert(PIPELINE_COLOR_PASS_FLAG_TRANSPARENT | PIPELINE_COLOR_PASS_FLAG_LIGHTMAP);
	valid_color_pass_pipelines.insert(PIPELINE_COLOR_PASS_FLAG_TRANSPARENT | PIPELINE_COLOR_PASS_FLAG_MULTIVIEW);
	valid_color_pass_pipelines.insert(PIPELINE_COLOR_PASS_FLAG_TRANSPARENT | PIPELINE_COLOR_PASS_FLAG_MOTION_VECTORS);
	valid_color_pass_pipelines.insert(PIPELINE_COLOR_PASS_FLAG_TRANSPARENT | PIPELINE_COLOR_PASS_FLAG_LIGHTMAP | PIPELINE_COLOR_PASS_FLAG_MULTIVIEW);
	valid_color_pass_pipelines.insert(PIPELINE_COLOR_PASS_FLAG_TRANSPARENT | PIPELINE_COLOR_PASS_FLAG_LIGHTMAP | PIPELINE_COLOR_PASS_FLAG_MOTION_VECTORS);
	valid_color_pass_pipelines.insert(PIPELINE_COLOR_PASS_FLAG_TRANSPARENT | PIPELINE_COLOR_PASS_FLAG_MULTIVIEW | PIPELINE_COLOR_PASS_FLAG_MOTION_VECTORS);
	valid_color_pass_pipelines.insert(PIPELINE_COLOR_PASS_FLAG_TRANSPARENT | PIPELINE_COLOR_PASS_FLAG_LIGHTMAP | PIPELINE_COLOR_PASS_FLAG_MULTIVIEW | PIPELINE_COLOR_PASS_FLAG_MOTION_VECTORS);
	valid_color_pass_pipelines.insert(PIPELINE_COLOR_PASS_FLAG_SEPARATE_SPECULAR);
	valid_color_pass_pipelines.insert(PIPELINE_COLOR_PASS_FLAG_SEPARATE_SPECULAR | PIPELINE_COLOR_PASS_FLAG_LIGHTMAP);
	valid_color_pass_pipelines.insert(PIPELINE_COLOR_PASS_FLAG_SEPARATE_SPECULAR | PIPELINE_COLOR_PASS_FLAG_MULTIVIEW);
	valid_color_pass_pipelines.insert(PIPELINE_COLOR_PASS_FLAG_SEPARATE_SPECULAR | PIPELINE_COLOR_PASS_FLAG_MOTION_VECTORS);