Replace phpdoc types with type annotations for private members

Change Iece78d81c33f9ac8d50b8e2d7bb9f9a06d2f11a4 introduced type
annotations for some private class properties to quiet a PHPCS
sniff (MissingDocumentationPrivate). Since mediawiki-codesniffer
v41 (T325201), the FunctionComment and Cleanup
PropertyDocumentation sniffs are more lenient about allowing
missing doc comments as long as information is provided by static
type.

Replace the phpdoc annotations with static types.

Bug: T330644
Change-Id: I421284245c289208a209acfbd710491dacaf8cbc

tests/unit/DataValue/ValuesFinderTest.php

@@ -22,8 +22,7 @@
  */
 class ValuesFinderTest extends TestCase {
 
-	/** @var array */
-	private static $propertyDataTypes = [
+	private static array $propertyDataTypes = [
 		'P23' => 'string',
 		'P42' => 'url',
 		'P44' => 'boolean',