fix: checkstyle

Signed-off-by: LE SAULNIER Kevin <[email protected]>

Author: LE SAULNIER Kevin

src/main/java/org/gridsuite/securityanalysis/server/entities/ContingencyLimitViolationEntity.java

@@ -8,7 +8,6 @@
 
 import com.powsybl.iidm.network.*;
 import com.powsybl.security.LimitViolation;
-import com.powsybl.security.LimitViolationType;
 import org.gridsuite.computation.utils.ComputationResultUtils;
 import jakarta.persistence.*;
 import lombok.*;