Add non-regression rule tests for strict comparison false positives

Add rule tests for bug-14407 and bug-13421 to verify that the strict
comparison rule no longer reports false positive errors on these files.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: 2 people

tests/PHPStan/Rules/Comparison/StrictComparisonOfDifferentTypesRuleTest.php

@@ -1172,4 +1172,16 @@ public function testBug11054(): void
 		]);
 	}
 
+	#[RequiresPhp('>= 8.1')]
+	public function testBug14407(): void
+	{
+		$this->analyse([__DIR__ . '/../../Analyser/nsrt/bug-14407.php'], []);
+	}
+
+	#[RequiresPhp('>= 8.1')]
+	public function testBug13421(): void
+	{
+		$this->analyse([__DIR__ . '/../../Analyser/nsrt/bug-13421.php'], []);
+	}
+
 }