updated test docker images

Author: rashtao

.github/workflows/maven.yml

@@ -21,10 +21,10 @@ jobs:
         docker-img:
           - docker.io/arangodb/arangodb:3.8.7
           - docker.io/arangodb/arangodb:3.9.3
-          - docker.io/arangodb/arangodb-preview:3.10.0-beta.1
+          - docker.io/arangodb/arangodb-preview:3.10-nightly
           - docker.io/arangodb/enterprise:3.8.7
           - docker.io/arangodb/enterprise:3.9.3
-          - docker.io/arangodb/enterprise-preview:3.10.0-beta.1
+          - docker.io/arangodb/enterprise-preview:3.10-nightly
         topology:
           - single
           - cluster