### 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)

rename_hint = " " + vformat(R"(Did you mean to use "%s"?)", String(renamed_function_name) + "()");
				}
			}
			push_error(vformat(R"*(Function "%s()" not found in base %s.%s)*", p_call->function_name, base_name, rename_hint), p_call->is_super ? p_call : p_call->callee);
#else
			push_error(vformat(R"*(Function "%s()" not found in base %s.)*", p_call->function_name, base_name), p_call->is_super ? p_call : p_call->callee);
#endif 
		} else if (!found && (!p_call->is_super && base_type.is_hard_type() && base_type.kind == GDScriptParser::DataType::NATIVE && base_type.is_meta_type)) {
			push_error(vformat(R"*(Static function "%s()" not found in base "%s".)*", p_call->function_name, base_type.native_type), p_call);
		}
	}
	if (call_type.is_coroutine && !p_is_await && !p_is_root) {
		push_error(vformat(R"*(Function "%s()" is a coroutine, so it must be called with "await".)*", p_call->function_name), p_call);
	}
	p_call->set_datatype(call_type);
}
void GDScriptAnalyzer::reduce_cast(GDScriptParser::CastNode *p_cast) {
	reduce_expression(p_cast->operand);
	GDScriptParser::DataType cast_type = type_from_metatype(resolve_datatype(p_cast->cast_type));
	if (!cast_type.is_set()) {
		mark_node_unsafe(p_cast);
		return;
	}
	p_cast->set_datatype(cast_type);
	if (p_cast->operand->is_constant) {
		update_const_expression_builtin_type(p_cast->operand, cast_type, "cast", true);
		if (cast_type.is_variant() || p_cast->operand->get_datatype() == cast_type) {
			p_cast->is_constant = true;
			p_cast->reduced_value = p_cast->operand->reduced_value;
		}