### 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.usage_defines["NORMAL_MAP_DEPTH"] = "@NORMAL_MAP";
		actions.usage_defines["COLOR"] = "#define COLOR_USED\n";
		actions.usage_defines["INSTANCE_CUSTOM"] = "#define ENABLE_INSTANCE_CUSTOM\n";
		actions.usage_defines["POSITION"] = "#define OVERRIDE_POSITION\n";
		actions.usage_defines["ALPHA_SCISSOR_THRESHOLD"] = "#define ALPHA_SCISSOR_USED\n";
		actions.usage_defines["ALPHA_HASH_SCALE"] = "#define ALPHA_HASH_USED\n";
		actions.usage_defines["ALPHA_ANTIALIASING_EDGE"] = "#define ALPHA_ANTIALIASING_EDGE_USED\n";
		actions.usage_defines["ALPHA_TEXTURE_COORDINATE"] = "@ALPHA_ANTIALIASING_EDGE";
		actions.usage_defines["SSS_STRENGTH"] = "#define ENABLE_SSS\n";
		actions.usage_defines["SSS_TRANSMITTANCE_DEPTH"] = "#define ENABLE_TRANSMITTANCE\n";
		actions.usage_defines["BACKLIGHT"] = "#define LIGHT_BACKLIGHT_USED\n";
		actions.usage_defines["SCREEN_UV"] = "#define SCREEN_UV_USED\n";
		actions.usage_defines["DIFFUSE_LIGHT"] = "#define USE_LIGHT_SHADER_CODE\n";
		actions.usage_defines["SPECULAR_LIGHT"] = "#define USE_LIGHT_SHADER_CODE\n";
		actions.usage_defines["FOG"] = "#define CUSTOM_FOG_USED\n";
		actions.usage_defines["RADIANCE"] = "#define CUSTOM_RADIANCE_USED\n";
		actions.usage_defines["IRRADIANCE"] = "#define CUSTOM_IRRADIANCE_USED\n";
		actions.usage_defines["MODEL_MATRIX"] = "#define MODEL_MATRIX_USED\n";
		actions.render_mode_defines["skip_vertex_transform"] = "#define SKIP_TRANSFORM_USED\n";
		actions.render_mode_defines["world_vertex_coords"] = "#define VERTEX_WORLD_COORDS_USED\n";
		actions.render_mode_defines["ensure_correct_normals"] = "#define ENSURE_CORRECT_NORMALS\n";
		actions.render_mode_defines["cull_front"] = "#define DO_SIDE_CHECK\n";
		actions.render_mode_defines["cull_disabled"] = "#define DO_SIDE_CHECK\n";
		actions.render_mode_defines["particle_trails"] = "#define USE_PARTICLE_TRAILS\n";
		actions.render_mode_defines["depth_draw_opaque"] = "#define USE_OPAQUE_PREPASS\n";
		bool force_lambert = GLOBAL_GET("rendering/shading/overrides/force_lambert_over_burley");
		if (!force_lambert) {
			actions.render_mode_defines["diffuse_burley"] = "#define DIFFUSE_BURLEY\n";
		}
		actions.render_mode_defines["diffuse_lambert_wrap"] = "#define DIFFUSE_LAMBERT_WRAP\n";