minor #62258 [JsonPath] Remove unused "nothing" property from JsonCrawler (yoeunes)

This PR was merged into the 7.4 branch.

Discussion
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[JsonPath] Remove unused "nothing" property from JsonCrawler

| Q | A
|---|---
| Branch? | 7.4
| Bug fix? | no
| New feature? | no
| Deprecations? | no
| Issues | n/a
| License | MIT

This PR removes the `private static \stdClass $nothing;` property from `JsonCrawler`, as it is no longer used and has been replaced by the `Nothing::Nothing` enum. See #61749

Commits
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436ab117960 [JsonPath] Remove unused "nothing" property from JsonCrawler

Author: nicolas-grekas

JsonCrawler.php

@@ -30,8 +30,6 @@
  */
 final class JsonCrawler implements JsonCrawlerInterface
 {
-    private static \stdClass $nothing;
-
     private const RFC9535_FUNCTIONS = [
         'length' => true,
         'count' => true,
@@ -831,8 +829,8 @@ private function compare(mixed $left, mixed $right, string $operator): bool
 
     private function compareEquality(mixed $left, mixed $right): bool
     {
-        $leftIsNothing = $left === Nothing::Nothing;
-        $rightIsNothing = $right === Nothing::Nothing;
+        $leftIsNothing = Nothing::Nothing === $left;
+        $rightIsNothing = Nothing::Nothing === $right;
 
         if (
             $leftIsNothing && $rightIsNothing