[ParserOutput] Remove deprecated ::getCategories() method

This was deprecated with warnings in 1.40.

Change-Id: I7b8a86f6efbdd86c1f493db6741c37bfb325e9bb

RELEASE-NOTES-1.42

@@ -240,6 +240,8 @@ because of Phabricator reports.
   - ipblocks
 * ParserOutput::setFlag() and ::getFlag(), deprecated in 1.38, were removed. You
   should use ::setOutputFlag() and ::getOutputFlag() instead.
+* ParserOutput::getCategories(), deprecated in 1.40, has been removed. You
+  should use ::getCategoryNames() and ::getCategorySortKey() instead.
 * The parser does not substitute the default category sort key at
   parse time; this is substituted when the category links table is
   updated instead.  As a result {{DEFAULTSORT}} will affect all the

includes/parser/ParserOutput.php

@@ -618,16 +618,6 @@ class ParserOutput extends CacheTime implements ContentMetadataCollector {
 		return array_map( 'strval', array_keys( $this->mCategories ) );
 	}
 
-	/**
-	 * @deprecated since 1.40; use ::getCategoryNames() and
-	 * ::getCategorySortKey() instead. For @internal use ::getCategoryMap()
-	 * may be used, but it is not recommended.
-	 */
-	public function &getCategories() {
-		wfDeprecated( __METHOD__, '1.40' );
-		return $this->mCategories;
-	}
-
 	/**
 	 * Return category names and sort keys as a map.
 	 *

tests/phpunit/includes/Output/OutputPageTest.php

@@ -1281,7 +1281,6 @@ class OutputPageTest extends MediaWikiIntegrationTestCase {
 		$op = $this->setupCategoryTests( $fakeResults, $variantLinkCallback );
 
 		$stubPO = $this->createParserOutputStub( [
-			'getCategories' => $args,
 			'getCategoryMap' => $args,
 		] );
 
@@ -1616,7 +1615,6 @@ class OutputPageTest extends MediaWikiIntegrationTestCase {
 		}
 
 		$arrayReturningMethods = [
-			'getCategories',
 			'getCategoryMap',
 			'getFileSearchOptions',
 			'getHeadItems',