Module alias behavior doesn't match docs
### Description

[The Nim manual states](https://nim-lang.org/docs/manual.html#modules-module-names-in-imports):
> A module alias can be introduced via the as keyword, after which the original module name is inaccessible

But the latest Nim version from the playground accepts this code:
```nim
import std/strutils as su
assert "no".repeat(3) == "nonono"
```
The module is still accessible without the alias.

### Nim Version

v2.2.0 from the playground

### Current Output

_No response_

### Expected Output

_No response_

### Known Workarounds

_No response_

### Additional Information

_No response_