### 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)

} else {
					HashSet<int> constants;
					for (int i = 0; i < switch_block->statements.size(); i++) { 
						ControlFlowNode *flow = static_cast<ControlFlowNode *>(switch_block->statements[i]);
						if (flow) {
							if (flow->flow_op == FLOW_OP_CASE) {
								if (flow->expressions[0]->type == Node::TYPE_CONSTANT) {
									ConstantNode *cn = static_cast<ConstantNode *>(flow->expressions[0]);
									if (!cn || cn->values.is_empty()) {
										return ERR_PARSE_ERROR;
									}
									if (constants.has(cn->values[0].sint)) {
										_set_error(vformat(RTR("Duplicated case label: %d."), cn->values[0].sint));
										return ERR_PARSE_ERROR;
									}
									constants.insert(cn->values[0].sint);
								} else if (flow->expressions[0]->type == Node::TYPE_VARIABLE) {
									VariableNode *vn = static_cast<VariableNode *>(flow->expressions[0]);
									if (!vn) {
										return ERR_PARSE_ERROR;
									}
									ConstantNode::Value v;
									_find_identifier(p_block, false, p_function_info, vn->name, nullptr, nullptr, nullptr, nullptr, nullptr, &v);
									if (constants.has(v.sint)) {
										_set_error(vformat(RTR("Duplicated case label: %d."), v.sint));
										return ERR_PARSE_ERROR;
									}
									constants.insert(v.sint);
								}
							} else if (flow->flow_op == FLOW_OP_DEFAULT) {