`excluded` names in `LtUnlintNonExistingDefect` are always empty in production

LtUnlintNonExistingDefect carries an excluded collection (src/main/java/org/eolang/lints/LtUnlintNonExistingDefect.java:34) and passes it to DefectMissing at line 74, where it is consulted at DefectMissing.java:50, :64 and :82. The only production callers, PkMono.java:53 and MonoLints.java:40, both use the one-argument constructor, which sets excluded to new ListOf<>() at line 42. Outside of tests every !this.excluded.contains(name) is always true, and the two-argument constructor is reached only from LtUnlintNonExistingDefectTest and DefectMissingTest.

The list existed to skip WPA lint names (PkMono passed new ListOf<>(new WpaLintNames()) since f5aef525). 235cda2d removed WPA and switched PkMono to the one-argument constructor but kept the parameter. Since then, returnsFalseWhenRangeReferencesExcludedAbsentLint in DefectMissingTest.java:104 locks down behavior no caller can trigger, and the real exclusion path, WithoutLints in MonoWithout.java:28, has a dead twin next to it.

Dropping the excluded attribute from both classes together with the two-argument constructor, and moving the tests to the one-argument form, leaves production behavior unchanged.

@yegor256

Start with src/main/java/org/eolang/lints/LtUnlintNonExistingDefect.java and DefectMissing.java, then inspect the production callers in PkMono.java and MonoLints.java. Run LtUnlintNonExistingDefectTest and DefectMissingTest, including the excluded-name case, and confirm the one-argument construction and existing production behavior remain covered without the unused exclusion path.