Remove unused JKS privateKeyPassword property from Couchbase

Closes gh-45883

Author: mhalbritter

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/couchbase/CouchbaseProperties.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2024 the original author or authors.
+ * Copyright 2012-2025 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -155,11 +155,6 @@ public static class Jks {
 			 */
 			private String password;
 
-			/**
-			 * Private key password for certificate-based cluster authentication.
-			 */
-			private String privateKeyPassword;
-
 			public String getLocation() {
 				return this.location;
 			}
@@ -176,14 +171,6 @@ public void setPassword(String password) {
 				this.password = password;
 			}
 
-			public String getPrivateKeyPassword() {
-				return this.privateKeyPassword;
-			}
-
-			public void setPrivateKeyPassword(String privateKeyPassword) {
-				this.privateKeyPassword = privateKeyPassword;
-			}
-
 		}
 
 	}