### Godot version

4.0.2.stable

### System information

Windows 10

### Issue description

Engine keeps spamming me this
![изображение](https://user-images.githubusercontent.com/89089095/232018878-1584ed55-5867-4883-9519-67b82ef93813.png)


### Steps to reproduce

No steps, issue happens from time to time absolutely randomly

### Minimal reproduction project

N/A
update_extents(assignment);
	make_completion_context(COMPLETION_ASSIGN, assignment);
#ifdef DEBUG_ENABLED
	bool has_operator = true;
#endif
	switch (previous.type) {
		case GDScriptTokenizer::Token::EQUAL:
			assignment->operation = AssignmentNode::OP_NONE;
			assignment->variant_op = Variant::OP_MAX;
#ifdef DEBUG_ENABLED
			has_operator = false;
#endif
			break;
		case GDScriptTokenizer::Token::PLUS_EQUAL:
			assignment->operation = AssignmentNode::OP_ADDITION;
			assignment->variant_op = Variant::OP_ADD;
			break;
		case GDScriptTokenizer::Token::MINUS_EQUAL:
			assignment->operation = AssignmentNode::OP_SUBTRACTION;
			assignment->variant_op = Variant::OP_SUBTRACT;
			break;
		case GDScriptTokenizer::Token::STAR_EQUAL:
			assignment->operation = AssignmentNode::OP_MULTIPLICATION;
			assignment->variant_op = Variant::OP_MULTIPLY;
			break;
		case GDScriptTokenizer::Token::STAR_STAR_EQUAL:
			assignment->operation = AssignmentNode::OP_POWER;
			assignment->variant_op = Variant::OP_POWER;
			break;
		case GDScriptTokenizer::Token::SLASH_EQUAL: