Remove unused JsonMappingException import from StatementTests

Co-authored-by: thomasturrell <1552612+thomasturrell@users.noreply.github.com>

Author: Copilot

xapi-model/src/test/java/dev/learning/xapi/model/StatementTests.java

@@ -16,7 +16,6 @@
 import static org.hamcrest.Matchers.startsWith;
 
 import com.fasterxml.jackson.core.JsonProcessingException;
-import com.fasterxml.jackson.databind.JsonMappingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.exc.InvalidFormatException;
 import com.fasterxml.jackson.databind.exc.InvalidTypeIdException;