Update nick-fields/retry action to v4

Author: renovate[bot]

.github/workflows/gametests.yml

@@ -57,7 +57,7 @@ jobs:
           distribution: 'microsoft'
           java-version: 21
       - name: 'Fetch modpack'
-        uses: nick-fields/retry@v3 # Retry, as some maven repos can be finicky
+        uses: nick-fields/retry@v4 # Retry, as some maven repos can be finicky
         with:
           timeout_minutes: 5
           max_attempts: 3