### 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)

Vector<ConstantNode::Value> values;
		for (int i = 1; i < op->arguments.size(); i++) {
			op->arguments.write[i] = _reduce_expression(p_block, op->arguments[i]);
			if (op->arguments[i]->type == Node::TYPE_CONSTANT) {
				ConstantNode *cn = static_cast<ConstantNode *>(op->arguments[i]);
				if (get_scalar_type(cn->datatype) == base) {
					for (int j = 0; j < cn->values.size(); j++) {
						values.push_back(cn->values[j]);
					}
				} else if (get_scalar_type(cn->datatype) == cn->datatype) {
					ConstantNode::Value v;
					if (!convert_constant(cn, base, &v)) {
						return p_node;
					}
					values.push_back(v);
				} else {
					return p_node;
				}
			} else {
				return p_node;
			}
		}
		if (values.size() == 1) {
			if (type >= TYPE_MAT2 && type <= TYPE_MAT4) {
				ConstantNode::Value value = values[0];
				ConstantNode::Value zero;
				zero.real = 0.0f;
				int size = 2 + (type - TYPE_MAT2);
				values.clear();
				for (int i = 0; i < size; i++) {