chore: fix simultaneous typos (#21837)

----

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* [x] Have you followed the guidelines in our [Contributing guide?](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md)

### Adding new Unconventional Dependencies:

* [ ] This PR adds new unconventional dependencies following the process described [here](https://github.com/aws/aws-cdk/blob/main/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/main/INTEGRATION_TESTS.md)?
	* [ ] Did you use `yarn integ` to deploy the infrastructure and generate the snapshot (i.e. `yarn integ` without `--dry-run`)?

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packages/aws-cdk/lib/cdk-toolkit.ts

@@ -930,7 +930,7 @@ interface WatchOptions extends Omit<CfnDeployOptions, 'execute'> {
   readonly traceLogs?: boolean;
 
   /**
-   * Maximum number of simulatenous deployments (dependency permitting) to execute.
+   * Maximum number of simultaneous deployments (dependency permitting) to execute.
    * The default is '1', which executes all deployments serially.
    *
    * @default 1
@@ -1009,7 +1009,7 @@ export interface DeployOptions extends CfnDeployOptions, WatchOptions {
   readonly cloudWatchLogMonitor?: CloudWatchLogEventMonitor;
 
   /**
-   * Maximum number of simulatenous deployments (dependency permitting) to execute.
+   * Maximum number of simultaneous deployments (dependency permitting) to execute.
    * The default is '1', which executes all deployments serially.
    *
    * @default 1

packages/aws-cdk/lib/cli.ts

@@ -147,7 +147,7 @@ async function parseCommandLineArguments() {
           "'true' by default, use --no-logs to turn off. " +
           "Only in effect if specified alongside the '--watch' option",
       })
-      .option('concurrency', { type: 'number', desc: 'Maximum number of simulatenous deployments (dependency permitting) to execute.', default: 1, requiresArg: true }),
+      .option('concurrency', { type: 'number', desc: 'Maximum number of simultaneous deployments (dependency permitting) to execute.', default: 1, requiresArg: true }),
     )
     .command('import [STACK]', 'Import existing resource(s) into the given STACK', (yargs: Argv) => yargs
       .option('execute', { type: 'boolean', desc: 'Whether to execute ChangeSet (--no-execute will NOT execute the ChangeSet)', default: true })
@@ -217,7 +217,7 @@ async function parseCommandLineArguments() {
         desc: 'Show CloudWatch log events from all resources in the selected Stacks in the terminal. ' +
           "'true' by default, use --no-logs to turn off",
       })
-      .option('concurrency', { type: 'number', desc: 'Maximum number of simulatenous deployments (dependency permitting) to execute.', default: 1, requiresArg: true }),
+      .option('concurrency', { type: 'number', desc: 'Maximum number of simultaneous deployments (dependency permitting) to execute.', default: 1, requiresArg: true }),
     )
     .command('destroy [STACKS..]', 'Destroy the stack(s) named STACKS', (yargs: Argv) => yargs
       .option('all', { type: 'boolean', default: false, desc: 'Destroy all available stacks' })