renovatebot(deps): update i2incommon/grouper docker tag to v5.15.1

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| [i2incommon/grouper](https://redirect.github.com/rocky-linux/rocky-toolbox-images) | patch | `5.15.0` -> `5.15.1` |

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ci/tests/grouper/docker-compose.yml

@@ -8,7 +8,7 @@ services:
       - POSTGRES_USER=postgres
       - POSTGRES_PASSWORD=pass
   grouper:
-    image: "i2incommon/grouper:5.15.0"
+    image: "i2incommon/grouper:5.15.1"
     restart: always
     ports:
       - '7443:8443'
@@ -24,7 +24,7 @@ services:
       - GROUPER_AUTO_DDL_UPTOVERSION=5.*.*
       - GROUPER_RUN_HSQLDB=false
   grouper-ws:
-    image: "i2incommon/grouper:5.15.0"
+    image: "i2incommon/grouper:5.15.1"
     restart: always
     ports:
       - '9443:8443'