### Godot version

4.0.beta14

### System information

windows 10, gles 3, nvidia graphics

### Issue description

SCREEN_TEXTURE  was dropped in beta 14. The suggested replacement is to use ```uniform sampler2D SCREEN_TEXTURE : hint_screen_texture, filter_linear_mipmaps;```, but filter_linear_mipmaps is not recognized as a valid shader type hint and a shader using it fails to compile.

### Steps to reproduce

Create a canvas item shader and use the filter_linear_mipmaps type hint with a sampler2D uniform.

### Minimal reproduction project

N/A
if (r_constant_value) {
			if (shader->constants[p_identifier].initializer && shader->constants[p_identifier].initializer->values.size() == 1) {
				*r_constant_value = shader->constants[p_identifier].initializer->values[0];
			}
		}
		if (r_type) {
			*r_type = IDENTIFIER_CONSTANT;
		}
		return true;
	}
	for (int i = 0; i < shader->functions.size(); i++) {
		if (!shader->functions[i].callable) {
			continue;
		}
		if (shader->functions[i].name == p_identifier) {
			if (r_data_type) {
				*r_data_type = shader->functions[i].function->return_type;
			}
			if (r_array_size) {
				*r_array_size = shader->functions[i].function->return_array_size;
			}
			if (r_type) {
				*r_type = IDENTIFIER_FUNCTION;
			}
			return true;
		}
	}
	return false;
}
bool ShaderLanguage::_validate_operator(OperatorNode *p_op, DataType *r_ret_type, int *r_ret_size) {