### 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)

}
						}
					} break;
					case TYPE_BVEC2:
					case TYPE_IVEC2:
					case TYPE_UVEC2:
					case TYPE_VEC2: {
						int l = ident.length();
						if (l == 1) {
							member_type = DataType(dt - 1);
						} else if (l == 2) {
							member_type = dt;
						} else if (l == 3) {
							member_type = DataType(dt + 1);
						} else if (l == 4) {
							member_type = DataType(dt + 2);
						} else {
							ok = false;
							break;
						}
						const char32_t *c = ident.ptr();
						for (int i = 0; i < l; i++) {
							switch (c[i]) {
								case 'r':
								case 'g':
									if (position_symbols.size() > 0 || texture_symbols.size() > 0) {
										mix_error = true;
										break;
									}
									if (!color_symbols.has(c[i])) {