chore(rds): Aurora Postgres 14.4 deprecated, 14.5 added (#22757)

Aurora Postgres 14.4 has been silently deprecated. The upgrade path is `14.3 -> 14.5`

`aws rds describe-db-engine-versions --engine aurora-postgresql`

![justin_justins-mbp___dev_hoverslam_core-network_aws](https://user-images.githubusercontent.com/224840/199680357-a45fcc58-2def-4c6a-9ba2-c107032dc160.png)

![Gamma_and_RDS_Management_Console](https://user-images.githubusercontent.com/224840/199680576-3bf6abc2-0136-4c6a-ad55-c17fd7fbaea5.png)

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packages/@aws-cdk/aws-rds/lib/cluster-engine.ts

@@ -669,8 +669,13 @@ export class AuroraPostgresEngineVersion {
   public static readonly VER_13_7 = AuroraPostgresEngineVersion.of('13.7', '13', { s3Import: true, s3Export: true });
   /** Version "14.3". */
   public static readonly VER_14_3 = AuroraPostgresEngineVersion.of('14.3', '14', { s3Import: true, s3Export: true });
-  /** Version "14.4". */
+  /**
+   *  Version "14.4".
+   * @deprecated Version 14.4 is no longer supported by Amazon RDS.
+   */
   public static readonly VER_14_4 = AuroraPostgresEngineVersion.of('14.4', '14', { s3Import: true, s3Export: true });
+  /** Version "14.5". */
+  public static readonly VER_14_5 = AuroraPostgresEngineVersion.of('14.5', '14', { s3Import: true, s3Export: true });
 
   /**
    * Create a new AuroraPostgresEngineVersion with an arbitrary version.