fix: restore IN/NOT_IN operator arms in SimpleEquationFilterType

The fix from #35 added these arms to `SimpleEquationElement::__invoke()` on
`main`. This branch had already moved that `match` into
`SimpleEquationFilterType::buildQuery()`, so the rebase dropped them.

Author: ericges

src/Filter/Type/SimpleEquationFilterType.php

@@ -58,7 +58,11 @@ public function buildQuery(FilterQueryBuilder $builder, array $options): void
             SqlEquationOperator::LESS_THAN_EQUALS => $builder->expr()->lte($operandLeft, ':eq_right'),
             SqlEquationOperator::LIKE => $builder->expr()->like($operandLeft, ':eq_right'),
             SqlEquationOperator::NOT_LIKE => $builder->expr()->notLike($operandLeft, ':eq_right'),
+            SqlEquationOperator::IN => $builder->expr()->in($operandLeft, ':eq_right'),
+            SqlEquationOperator::NOT_IN => $builder->expr()->notIn($operandLeft, ':eq_right'),
             SqlEquationOperator::IS_NULL => $builder->expr()->isNull($operandLeft),
+            // the default arm below is a runtime safety net for operators added to the enum later
+            // @phpstan-ignore match.alwaysTrue
             SqlEquationOperator::IS_NOT_NULL => $builder->expr()->isNotNull($operandLeft),
             default => null,
         };