Polishing.

Remove invalid annotation usage.

See #2152

spring-data-relational/src/main/java/org/springframework/data/relational/core/conversion/AbstractRelationalConverter.java

@@ -17,7 +17,6 @@ package org.springframework.data.relational.core.conversion;
 
 import java.util.Collections;
 
-import org.jetbrains.annotations.NotNull;
 import org.springframework.core.convert.ConversionService;
 import org.springframework.core.convert.support.ConfigurableConversionService;
 import org.springframework.core.convert.support.DefaultConversionService;
@@ -76,7 +75,6 @@ public abstract class AbstractRelationalConverter implements RelationalConverter
 		conversions.registerConvertersIn(this.conversionService);
 	}
 
-	@NotNull
 	private static DefaultConversionService createBaseConversionService() {
 
 		DefaultConversionService conversionService = new DefaultConversionService();

spring-data-relational/src/main/java/org/springframework/data/relational/core/dialect/OracleDialect.java

@@ -15,11 +15,10 @@
  */
 package org.springframework.data.relational.core.dialect;
 
-import static java.util.Arrays.asList;
+import static java.util.Arrays.*;
 
 import java.util.Collection;
 
-import org.jetbrains.annotations.NotNull;
 import org.springframework.core.convert.converter.Converter;
 import org.springframework.data.convert.WritingConverter;
 import org.springframework.data.relational.core.sql.SqlIdentifier;
@@ -55,7 +54,7 @@ public class OracleDialect extends AnsiDialect {
 		}
 
 		@Override
-		public String createSequenceQuery(@NotNull SqlIdentifier sequenceName) {
+		public String createSequenceQuery(SqlIdentifier sequenceName) {
 			return "SELECT %s.nextval FROM DUAL".formatted(sequenceName.toSql(INSTANCE.getIdentifierProcessing()));
 		}
 	};