chore(lambda): update lambda runtimes deprecation warnings (#19938)

This PR mainly addresses `python3.6` deprecation, but it also updates deprecation verbiage for other runtimes as well.

```
Hello,

We are contacting you as we have identified that your AWS Account currently has one or more Lambda functions using Python 3.6 runtime.

We are ending support for Python 3.6 in AWS Lambda. This follows Python 3.6 End-Of-Life (EOL) reached on December 23, 2021 [1].

As described in the Lambda runtime support policy [2], end of support for language runtimes in Lambda happens in two stages. Starting July 18, 2022, Lambda will no longer apply security patches and other updates to the Python 3.6 runtime used by Lambda functions, and functions using Python 3.6 will no longer be eligible for technical support. In addition, you will no longer be able to create new Lambda functions using the Python 3.6 runtime. Starting August 17, 2022, you will no longer be able to update existing functions using the Python 3.6 runtime.

We recommend that you upgrade your existing Python 3.6 functions to Python 3.9 before August 17, 2022.

End of support does not impact function execution. Your functions will continue to run. However, they will be running on an unsupported runtime which is no longer maintained or patched by the AWS Lambda team.

The following command shows how to use the AWS CLI [3] to list all functions in a specific region using Python 3.6. To find all such functions in your account, repeat this command for each region:

aws lambda list-functions --function-version ALL --region us-east-1 --output text --query "Functions[?Runtime=='python3.6'].FunctionArn"

If you have any concerns or require further assistance, please contact AWS Support [4].
```

https://docs.aws.amazon.com/lambda/latest/dg/runtime-support-policy.html

Link #19988 

----

### All Submissions:

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### Adding new Unconventional Dependencies:

* [ ] This PR adds new unconventional dependencies following the process described [here](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md/#adding-new-unconventional-dependencies)

### New Features

* [ ] Have you added the new feature to an [integration test](https://github.com/aws/aws-cdk/blob/master/INTEGRATION_TESTS.md)?
	* [ ] Did you use `yarn integ` to deploy the infrastructure and generate the snapshot (i.e. `yarn integ` without `--dry-run`)?

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

packages/@aws-cdk/aws-lambda/lib/runtime.ts

@@ -42,30 +42,31 @@ export class Runtime {
 
   /**
    * The NodeJS runtime (nodejs)
-   * Legacy runtime no longer supported by AWS Lambda.
+   * @deprecated Legacy runtime no longer supported by AWS Lambda. Migrate to the latest NodeJS runtime.
    */
   public static readonly NODEJS = new Runtime('nodejs', RuntimeFamily.NODEJS, { supportsInlineCode: true });
 
   /**
    * The NodeJS 4.3 runtime (nodejs4.3)
-   * Legacy runtime no longer supported by AWS Lambda.
+   * @deprecated Legacy runtime no longer supported by AWS Lambda. Migrate to the latest NodeJS runtime.
    */
   public static readonly NODEJS_4_3 = new Runtime('nodejs4.3', RuntimeFamily.NODEJS, { supportsInlineCode: true });
 
   /**
    * The NodeJS 6.10 runtime (nodejs6.10)
-   * Legacy runtime no longer supported by AWS Lambda.
+   * @deprecated Legacy runtime no longer supported by AWS Lambda. Migrate to the latest NodeJS runtime.
    */
   public static readonly NODEJS_6_10 = new Runtime('nodejs6.10', RuntimeFamily.NODEJS, { supportsInlineCode: true });
 
   /**
    * The NodeJS 8.10 runtime (nodejs8.10)
-   * Legacy runtime no longer supported by AWS Lambda.
+   * @deprecated Legacy runtime no longer supported by AWS Lambda. Migrate to the latest NodeJS runtime.
    */
   public static readonly NODEJS_8_10 = new Runtime('nodejs8.10', RuntimeFamily.NODEJS, { supportsInlineCode: true });
 
   /**
    * The NodeJS 10.x runtime (nodejs10.x)
+   * @deprecated Legacy runtime no longer supported by AWS Lambda. Migrate to the latest NodeJS runtime.
    */
   public static readonly NODEJS_10_X = new Runtime('nodejs10.x', RuntimeFamily.NODEJS, { supportsInlineCode: true });
 
@@ -81,11 +82,13 @@ export class Runtime {
 
   /**
    * The Python 2.7 runtime (python2.7)
+   * @deprecated Legacy runtime no longer supported by AWS Lambda. Migrate to the latest Python runtime.
    */
   public static readonly PYTHON_2_7 = new Runtime('python2.7', RuntimeFamily.PYTHON, { supportsInlineCode: true });
 
   /**
    * The Python 3.6 runtime (python3.6)
+   * @deprecated Legacy runtime no longer supported by AWS Lambda. Migrate to the latest Python runtime.
    */
   public static readonly PYTHON_3_6 = new Runtime('python3.6', RuntimeFamily.PYTHON, {
     supportsInlineCode: true,
@@ -144,18 +147,19 @@ export class Runtime {
 
   /**
    * The .NET Core 1.0 runtime (dotnetcore1.0)
-   * Legacy runtime no longer supported by AWS Lambda.
+   * Legacy runtime no longer supported by AWS Lambda. Migrate to the latest .NET Core runtime.
    */
   public static readonly DOTNET_CORE_1 = new Runtime('dotnetcore1.0', RuntimeFamily.DOTNET_CORE);
 
   /**
    * The .NET Core 2.0 runtime (dotnetcore2.0)
-   * Legacy runtime no longer supported by AWS Lambda.
+   * Legacy runtime no longer supported by AWS Lambda. Migrate to the latest .NET Core runtime.
    */
   public static readonly DOTNET_CORE_2 = new Runtime('dotnetcore2.0', RuntimeFamily.DOTNET_CORE);
 
   /**
    * The .NET Core 2.1 runtime (dotnetcore2.1)
+   * Legacy runtime no longer supported by AWS Lambda. Migrate to the latest .NET Core runtime.
    */
   public static readonly DOTNET_CORE_2_1 = new Runtime('dotnetcore2.1', RuntimeFamily.DOTNET_CORE);
 
@@ -171,6 +175,7 @@ export class Runtime {
 
   /**
    * The Ruby 2.5 runtime (ruby2.5)
+   * Legacy runtime no longer supported by AWS Lambda. Migrate to the latest Ruby runtime.
    */
   public static readonly RUBY_2_5 = new Runtime('ruby2.5', RuntimeFamily.RUBY);