no warning on contextual-store if declaring it as a parameter / variable

[tanhauhau]

This PR fix for the following error:

<script>
      function test(store) {
		// should not error when declaring the parameter as `$store`
		return derived(store, $store => {
		});
	}
</script>

Before submitting the PR, please make sure you do the following

• This message body should clearly illustrate what problems it solves.
• Ideally, include a test that fails without this PR but passes with it.

Tests

• Run the tests with npm test and lint the project with npm run lint