[infrastructure] move infered nullness warnings to error and update EEA (#8949)

Signed-off-by: Jan N. Klug <jan.n.klug@rub.de>

bundles/org.openhab.persistence.mapdb/src/test/java/org/openhab/persistence/mapdb/StateTypeAdapterTest.java

@@ -17,6 +17,7 @@ import static org.hamcrest.MatcherAssert.assertThat;
 
 import java.math.BigDecimal;
 import java.util.List;
+import java.util.Objects;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
@@ -75,7 +76,7 @@ public class StateTypeAdapterTest {
     @MethodSource
     public void readWriteRoundtripShouldRecreateTheWrittenState(State state) {
         String json = mapper.toJson(state);
-        State actual = mapper.fromJson(json, State.class);
+        State actual = Objects.requireNonNull(mapper.fromJson(json, State.class));
         assertThat(actual, is(equalTo(state)));
     }