Docker not available in build system
The tests for the GraphDB require Docker to start a Neo4J instance. Currently this doesn't work:
```
68411 [ERROR] eu.gaiax.difs.fc.core.service.graphdb.GraphTest Time elapsed: 0.217 s <<< ERROR!
java.lang.IllegalStateException: Could not find a valid Docker environment. Please see logs and check configuration
at eu.gaiax.difs.fc.core.service.graphdb.GraphTest.setupContainer(GraphTest.java:36)
```
See https://gitlab.com/gaia-x/data-infrastructure-federation-services/cat/fc-service/-/pipelines/604698280
issue