refactor(tests): returnValue is deprecated

Signed-off-by: Ferdinand Thiessen <[email protected]>

Author: susnux

tests/lib/Cache/FileCacheTest.php

@@ -150,7 +150,8 @@ public function testGarbageCollectIgnoreLockedKeys($testException): void {
 			->method('filemtime')
 			->willReturn(100);
 		$mockStorage->expects($this->atLeastOnce())
-			->method('unlink')->willReturnOnConsecutiveCalls($this->throwException($testException), $this->returnValue(true));
+			->method('unlink')
+			->willReturnOnConsecutiveCalls($this->throwException($testException), true);
 
 		$this->instance->set('key1', 'value1');
 		$this->instance->set('key2', 'value2');