### 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)

} else {
#ifdef SUGGEST_GODOT4_RENAMES
		String rename_hint = String();
		if (GLOBAL_GET(GDScriptWarning::get_settings_path_from_code(GDScriptWarning::Code::RENAMED_IN_GODOT_4_HINT)).booleanize()) {
			const char *renamed_identifier_name = check_for_renamed_identifier(name, p_identifier->type);
			if (renamed_identifier_name) {
				rename_hint = " " + vformat(R"(Did you mean to use "%s"?)", renamed_identifier_name);
			}
		}
		push_error(vformat(R"(Identifier "%s" not declared in the current scope.%s)", name, rename_hint), p_identifier);
#else
		push_error(vformat(R"(Identifier "%s" not declared in the current scope.)", name), p_identifier);
#endif 
	}
	GDScriptParser::DataType dummy;
	dummy.kind = GDScriptParser::DataType::VARIANT;
	p_identifier->set_datatype(dummy); 
}
void GDScriptAnalyzer::reduce_lambda(GDScriptParser::LambdaNode *p_lambda) {
	
	GDScriptParser::DataType lambda_type;
	lambda_type.type_source = GDScriptParser::DataType::ANNOTATED_INFERRED;
	lambda_type.kind = GDScriptParser::DataType::BUILTIN;
	lambda_type.builtin_type = Variant::CALLABLE;
	p_lambda->set_datatype(lambda_type);
	if (p_lambda->function == nullptr) {
		return;
	}
	lambda_stack.push_back(p_lambda);
	resolve_function_signature(p_lambda->function, p_lambda, true);