Remove obsolete code from internal HibernateTransactionObject

See gh-35111

Author: sbrannen

spring-orm/src/main/java/org/springframework/orm/jpa/hibernate/HibernateTransactionManager.java

@@ -720,10 +720,6 @@ protected void doCleanupAfterCompletion(Object transaction) {
 			// Else, we need to rely on the connection pool to perform proper cleanup.
 			try {
 				Connection con = session.getJdbcCoordinator().getLogicalConnection().getPhysicalConnection();
-				Integer previousHoldability = txObject.getPreviousHoldability();
-				if (previousHoldability != null) {
-					con.setHoldability(previousHoldability);
-				}
 				DataSourceUtils.resetConnectionAfterTransaction(
 						con, txObject.getPreviousIsolationLevel(), txObject.isReadOnly());
 			}
@@ -771,7 +767,7 @@ protected void disconnectOnCompletion(Session session) {
 
 	/**
 	 * Hibernate transaction object, representing a SessionHolder.
-	 * Used as transaction object by HibernateTransactionManager.
+	 * <p>Used as transaction object by HibernateTransactionManager.
 	 */
 	private class HibernateTransactionObject extends JdbcTransactionObjectSupport {
 
@@ -783,8 +779,6 @@ private class HibernateTransactionObject extends JdbcTransactionObjectSupport {
 
 		private boolean needsConnectionReset;
 
-		private @Nullable Integer previousHoldability;
-
 		public void setSession(Session session) {
 			this.sessionHolder = new SessionHolder(session);
 			this.newSessionHolder = true;
@@ -828,14 +822,6 @@ public boolean needsConnectionReset() {
 			return this.needsConnectionReset;
 		}
 
-		public void setPreviousHoldability(@Nullable Integer previousHoldability) {
-			this.previousHoldability = previousHoldability;
-		}
-
-		public @Nullable Integer getPreviousHoldability() {
-			return this.previousHoldability;
-		}
-
 		public boolean hasSpringManagedTransaction() {
 			return (this.sessionHolder != null && this.sessionHolder.getTransaction() != null);
 		}