`@rpglint-skip` not working for multi-location errors (e.g. `StringLiteralDupe`, `NoUnreferenced`)

### Description

When using the `@rpglint-skip` or `@rpglint-skip-rules` annotation, some error types are not skipped as expected.

This seems to affect rules that report **multiple locations for a single logical issue**, such as:

* `StringLiteralDupe`
* `NoUnreferenced`
* `IncorrectVariableCase`

Even when the annotation is placed correctly, errors are still reported for lines that should be skipped.
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### Example

```rpg
**free
dcl-s myVar char(10);

// @rpglint-skip
myvar = 'first';

myvar = 'second';

return;
```

#### Expected Behavior

Only one `IncorrectVariableCase` error should be reported (for the second assignment).

The first assignment (`myvar = 'first';`) should be skipped due to the `@rpglint-skip` annotation.

#### Actual Behavior

Two `IncorrectVariableCase` errors are reported:

* One for `myvar = 'first';` (should be skipped)
* One for `myvar = 'second';`

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### Additional Context

This behavior appears to occur with rules that perform some lookup logic. If all errors for a Literal are skiped it gain works like intended.

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I'm already working on a solution. The PR should be ready by tomorrow.