feat(cache): make assertLocked ensure that the checked lock has an expiration (#1758)

Author: xHeaven

packages/cache/src/Testing/TestingLock.php

@@ -66,6 +66,11 @@ public function assertLocked(null|Stringable|string $by = null, null|DateTimeInt
                 $until = DateTime::now()->plus($until);
             }
 
+            Assert::assertNotNull(
+                actual: $this->expiration,
+                message: "Expected lock `{$this->key}` to have an expiration, but it has none.",
+            );
+
             Assert::assertTrue(
                 condition: $this->expiration->afterOrAtTheSameTime($until),
                 message: "Expected lock `{$this->key}` to expire at or after `{$until}`, but it expires at `{$this->expiration}`.",