chore(rds): add support for new PostgreSQL minor versions (#18640)

Amazon RDS for PostgreSQL supports new minor versions 13.5, 12.9, 11.14, 10.19, and 9.6.24.

https://aws.amazon.com/about-aws/whats-new/2022/01/amazon-rds-postgresql-amazon-rds-outposts-postgresql-minor-versions/

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: nikovirtala

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

@@ -799,6 +799,11 @@ export class PostgresEngineVersion {
    * @deprecated PostgreSQL 9.6 will reach end of life in November 2021
   */
   public static readonly VER_9_6_23 = PostgresEngineVersion.of('9.6.23', '9.6');
+  /**
+   * Version "9.6.24".
+   * @deprecated PostgreSQL 9.6 will reach end of life in November 2021
+  */
+  public static readonly VER_9_6_24 = PostgresEngineVersion.of('9.6.24', '9.6');
 
   /** Version "10" (only a major version, without a specific minor version). */
   public static readonly VER_10 = PostgresEngineVersion.of('10', '10');
@@ -834,6 +839,8 @@ export class PostgresEngineVersion {
   public static readonly VER_10_17 = PostgresEngineVersion.of('10.17', '10', { s3Import: true, s3Export: true });
   /** Version "10.18". */
   public static readonly VER_10_18 = PostgresEngineVersion.of('10.18', '10', { s3Import: true, s3Export: true });
+  /** Version "10.19". */
+  public static readonly VER_10_19 = PostgresEngineVersion.of('10.19', '10', { s3Import: true, s3Export: true });
 
   /** Version "11" (only a major version, without a specific minor version). */
   public static readonly VER_11 = PostgresEngineVersion.of('11', '11', { s3Import: true });
@@ -861,6 +868,8 @@ export class PostgresEngineVersion {
   public static readonly VER_11_12 = PostgresEngineVersion.of('11.12', '11', { s3Import: true, s3Export: true });
   /** Version "11.13". */
   public static readonly VER_11_13 = PostgresEngineVersion.of('11.13', '11', { s3Import: true, s3Export: true });
+  /** Version "11.14". */
+  public static readonly VER_11_14 = PostgresEngineVersion.of('11.14', '11', { s3Import: true, s3Export: true });
 
   /** Version "12" (only a major version, without a specific minor version). */
   public static readonly VER_12 = PostgresEngineVersion.of('12', '12', { s3Import: true });
@@ -878,6 +887,8 @@ export class PostgresEngineVersion {
   public static readonly VER_12_7 = PostgresEngineVersion.of('12.7', '12', { s3Import: true, s3Export: true });
   /** Version "12.8". */
   public static readonly VER_12_8 = PostgresEngineVersion.of('12.8', '12', { s3Import: true, s3Export: true });
+  /** Version "12.9". */
+  public static readonly VER_12_9 = PostgresEngineVersion.of('12.9', '12', { s3Import: true, s3Export: true });
 
   /** Version "13" (only a major version, without a specific minor version). */
   public static readonly VER_13 = PostgresEngineVersion.of('13', '13', { s3Import: true, s3Export: true });
@@ -889,6 +900,8 @@ export class PostgresEngineVersion {
   public static readonly VER_13_3 = PostgresEngineVersion.of('13.3', '13', { s3Import: true, s3Export: true });
   /** Version "13.4". */
   public static readonly VER_13_4 = PostgresEngineVersion.of('13.4', '13', { s3Import: true, s3Export: true });
+  /** Version "13.5". */
+  public static readonly VER_13_5 = PostgresEngineVersion.of('13.5', '13', { s3Import: true, s3Export: true });
 
   /**
    * Create a new PostgresEngineVersion with an arbitrary version.