docs(iot-actions-alpha): fix typos (#32891)

### Issue # (if applicable)

None

### Reason for this change

Fixed typos in code comments.


### Checklist
- [x] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

----

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

Author: andyu17

packages/@aws-cdk/aws-iot-actions-alpha/lib/firehose-put-record-action.ts

@@ -24,7 +24,7 @@ export enum FirehoseRecordSeparator {
   WINDOWS_NEWLINE = '\r\n',
 
   /**
-   * Separate by a commma
+   * Separate by a comma
    */
   COMMA = ',',
 }

packages/@aws-cdk/aws-iot-actions-alpha/lib/kinesis-put-record-action.ts

@@ -14,7 +14,7 @@ export interface KinesisPutRecordActionProps extends CommonActionProps {
    *
    * @see https://docs.aws.amazon.com/iot/latest/developerguide/iot-substitution-templates.html
    *
-   * You can use the expression '${newuuid()}' if your payload does not have a high cardinarity property.
+   * You can use the expression '${newuuid()}' if your payload does not have a high cardinality property.
    * If you use empty string, this action use no partition key and all records will put same one shard.
    *
    * @see https://docs.aws.amazon.com/kinesis/latest/APIReference/API_PutRecord.html#API_PutRecord_RequestParameters

packages/@aws-cdk/aws-iot-actions-alpha/lib/step-functions-state-machine-action.ts

@@ -28,7 +28,7 @@ export class StepFunctionsStateMachineAction implements iot.IAction {
   private readonly role?: iam.IRole;
 
   /**
-   * @param stateMachine The Step Functions Start Machine which shoud be executed.
+   * @param stateMachine The Step Functions Start Machine which should be executed.
    * @param props Optional properties to not use default
    */
   constructor(private readonly stateMachine: stepfunctions.IStateMachine, props?: StepFunctionsStateMachineActionProps) {

packages/@aws-cdk/aws-iot-actions-alpha/test/kinesis-firehose/firehose-put-record-action.test.ts

@@ -90,7 +90,7 @@ test('can set batchMode', () => {
   });
 });
 
-test('can set separotor', () => {
+test('can set separator', () => {
   // GIVEN
   const stack = new cdk.Stack();
   const topicRule = new iot.TopicRule(stack, 'MyTopicRule', {