### Godot version

v4.0.rc1.official [8843d9ad3]

### System information

Lubuntu

### Issue description

You can't use + or += to mutate typed arrays.

It seems to be not correctly getting the type information from the second operand.

An erudite poster on the discord puts it differently:
> it's more like operator + doesn't retain Array typing
> the syntax for Array Concatenation via operators, but the idea gets across i think


The error you see is:
```Trying to assign an array of type "Array" to a variable of type "Array[int]".```


### Steps to reproduce

```
	var Alice: Array[int] = [1,2,3]
	var Bob: Array[int] = [4,5,6]
	Alice += Bob
```
This will crash with the above error message.

### Minimal reproduction project

[plus_syntax_broken_demo_project.zip](https://github.com/godotengine/godot/files/10694514/plus_syntax_broken_demo_project.zip)

case GDScriptParser::PatternNode::PT_DICTIONARY:
			for (int i = 0; i < p_match_pattern->dictionary.size(); i++) {
				if (p_match_pattern->dictionary[i].key) {
					reduce_expression(p_match_pattern->dictionary[i].key);
					if (!p_match_pattern->dictionary[i].key->is_constant) {
						push_error(R"(Expression in dictionary pattern key must be a constant.)", p_match_pattern->dictionary[i].key);
					}
				}
				if (p_match_pattern->dictionary[i].value_pattern) {
					resolve_match_pattern(p_match_pattern->dictionary[i].value_pattern, nullptr);
					decide_suite_type(p_match_pattern, p_match_pattern->dictionary[i].value_pattern);
				}
			}
			result = p_match_pattern->get_datatype();
			break;
		case GDScriptParser::PatternNode::PT_WILDCARD:
		case GDScriptParser::PatternNode::PT_REST:
			result.kind = GDScriptParser::DataType::VARIANT;
			break;
	}
	p_match_pattern->set_datatype(result);
}
void GDScriptAnalyzer::resolve_return(GDScriptParser::ReturnNode *p_return) {
	GDScriptParser::DataType result;
	GDScriptParser::DataType expected_type;
	bool has_expected_type = parser->current_function != nullptr;
	if (has_expected_type) {
		expected_type = parser->current_function->get_datatype();
	}
	if (p_return->return_value != nullptr) {