build: Update MediaWiki requirement to 1.42

All extensions in the MediaWiki tarball are expected to track MediaWiki's release directly.

Change-Id: I29fd0a17e6f5bf8da5f4a436fbfaa08585218963

extension.json

@@ -4,7 +4,7 @@
 		"Max Semenik"
 	],
 	"requires": {
-		"MediaWiki": ">= 1.41"
+		"MediaWiki": ">= 1.42"
 	},
 	"url": "https://www.mediawiki.org/wiki/Extension:TextExtracts",
 	"descriptionmsg": "textextracts-desc",