### Godot version

4.0.beta16

### System information

Windows 10 Pro x64, GLES3, RTX 3080 Ti (528.02)

### Issue description

In Compatibility/GLES3 back-end, shaders which use a uniform to get the normal roughness buffer cannot compile. For example, the shader:
```glsl
shader_type spatial;

uniform sampler2D normal_roughness_texture : hint_normal_roughness_texture;

void fragment() {
    vec4 sample = texture(normal_roughness_texture, UV);
}
```
results in an error in the output:
```
  drivers/gles3/shader_gles3.cpp:242 - SceneShaderGLES3: Fragment shader compilation failed:
  0(890) : error C1503: undefined variable "normal_roughness_buffer"
  
  drivers/gles3/shader_gles3.cpp:342 - Method/function failed.
```

If I switch over to the Mobile or Forward+ backends, there is no shader compilation error.

### Steps to reproduce

Open the attached reproduction in the 4.0.beta16 editor.

When the scene is opened, the error is produced automatically:
1. Open `scene.tscn`
2. Open Output to review error

When the scene is saved with any changes made to the shader, the same error is also produced:
1. Open `scene.tscn`
2. Open `example.gdshader` in the shader editor.
3. Make a compile-able change to the shader.
4. Save the scene
5. Open Output to review the error

### Minimal reproduction project

[NormalRoughnessTexture_GLES3_Error.zip](https://github.com/godotengine/godot/files/10534253/NormalRoughnessTexture_GLES3_Error.zip)

}
						decl.size = array_size;
						fixed_array_size = true;
						tk = _get_token();
					}
				}
				if (tk.type != TK_IDENTIFIER) {
					_set_error(RTR("Expected an identifier."));
					return ERR_PARSE_ERROR;
				}
				StringName name = tk.text;
				ShaderLanguage::IdentifierType itype;
				if (_find_identifier(p_block, true, p_function_info, name, (ShaderLanguage::DataType *)nullptr, &itype)) {
					if (itype != IDENTIFIER_FUNCTION) {
						_set_redefinition_error(String(name));
						return ERR_PARSE_ERROR;
					}
				}
				decl.name = name;
#ifdef DEBUG_ENABLED
				if (check_warnings && HAS_WARNING(ShaderWarning::UNUSED_LOCAL_VARIABLE_FLAG) && p_block) {
					FunctionNode *parent_function = nullptr;
					{
						BlockNode *block = p_block;
						while (block && !block->parent_function) {
							block = block->parent_block;
						}
						parent_function = block->parent_function;
					}
					if (parent_function) {