refs #22123 [adlr] add latest package hash for result grouping to handle...

refs #22123 [adlr] add latest package hash for result grouping to handle groups with empty match_str

composer.lock

@@ -673,7 +673,7 @@
             "source": {
                 "type": "git",
                 "url": "https://git.sc.uni-leipzig.de/ubl/finc/packages/vufind-results-grouping.git",
-                "reference": "1fb0443a7713b459f6c83991aacc11a4e1abdf45"
+                "reference": "1f888b606d99f5c55a6e76e24a292437c4df23cd"
             },
             "require": {
                 "php": ">=7.1"