### 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)

continue; 
		} else if (tk.type == TK_OP_SUB || tk.type == TK_OP_NOT || tk.type == TK_OP_BIT_INVERT || tk.type == TK_OP_INCREMENT || tk.type == TK_OP_DECREMENT) {
			Expression e;
			e.is_op = true;
			switch (tk.type) {
				case TK_OP_SUB:
					e.op = OP_NEGATE;
					break;
				case TK_OP_NOT:
					e.op = OP_NOT;
					break;
				case TK_OP_BIT_INVERT:
					e.op = OP_BIT_INVERT;
					break;
				case TK_OP_INCREMENT:
					e.op = OP_INCREMENT;
					break;
				case TK_OP_DECREMENT:
					e.op = OP_DECREMENT;
					break;
				default:
					ERR_FAIL_V(nullptr);
			}
			expression.push_back(e);
			continue;
		} else {
			bool valid = false;
			if (p_block && p_block->block_type == BlockNode::BLOCK_TYPE_FOR_EXPRESSION && tk.type == TK_PARENTHESIS_CLOSE) {
				valid = true;
				_set_tkpos(prepos);