### 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)

HashMap<Variant, GDScriptParser::ExpressionNode *, VariantHasher, StringLikeVariantComparator> elements;
	for (int i = 0; i < p_dictionary->elements.size(); i++) {
		const GDScriptParser::DictionaryNode::Pair &element = p_dictionary->elements[i];
		if (p_dictionary->style == GDScriptParser::DictionaryNode::PYTHON_DICT) {
			reduce_expression(element.key);
		}
		reduce_expression(element.value);
		if (element.key->is_constant) {
			if (elements.has(element.key->reduced_value)) {
				push_error(vformat(R"(Key "%s" was already used in this dictionary (at line %d).)", element.key->reduced_value, elements[element.key->reduced_value]->start_line), element.key);
			} else {
				elements[element.key->reduced_value] = element.value;
			}
		}
	}
	
	GDScriptParser::DataType dict_type;
	dict_type.type_source = GDScriptParser::DataType::ANNOTATED_EXPLICIT;
	dict_type.kind = GDScriptParser::DataType::BUILTIN;
	dict_type.builtin_type = Variant::DICTIONARY;
	dict_type.is_constant = true;
	p_dictionary->set_datatype(dict_type);
}
void GDScriptAnalyzer::reduce_get_node(GDScriptParser::GetNodeNode *p_get_node) {
	GDScriptParser::DataType result;
	result.type_source = GDScriptParser::DataType::ANNOTATED_EXPLICIT;
	result.kind = GDScriptParser::DataType::NATIVE;
	result.native_type = SNAME("Node");
	result.builtin_type = Variant::OBJECT;
	if (!ClassDB::is_parent_class(parser->current_class->base_type.native_type, result.native_type)) {