Fix removing elseifs that should be skipped

I accidentally put an && ! condition rather than
an ||, causing elseifs with skippable exprs to get
removed rather than being skipped.

- Fix the conditional
- Add a test for skippable exprs in elseif
  condition.

Author: john-shaffer

rules-tests/DeadCode/Rector/If_/RemoveDeadIfBlocksRector/Fixture/skip_property_fetch.php.inc

@@ -0,0 +1,17 @@
+<?php
+
+namespace Rector\Tests\DeadCode\Rector\If_\RemoveDeadIfBlocksRector\Fixture;
+
+class SkipPropertyFetch
+{
+    public function run($obj, $condition)
+    {
+        if ($condition) {
+            echo '1';
+        } elseif ($obj->v) {
+            echo '2';
+        }
+    }
+}
+
+?>

rules/DeadCode/Rector/If_/RemoveDeadIfBlocksRector.php

@@ -112,7 +112,7 @@ public function refactor(Node $node): int|null|If_
             foreach ($node->elseifs as $elseif) {
                 $keep_elseifs = array_filter(
                     $node->elseifs,
-                    fn ($elseif) => $elseif->stmts !== [] && ! $this->shouldSkipExpr($elseif->cond)
+                    fn ($elseif) => $elseif->stmts !== [] || $this->shouldSkipExpr($elseif->cond)
                 );
                 if (count($node->elseifs) !== count($keep_elseifs)) {
                     $node->elseifs = $keep_elseifs;