docs(core): fix docs for Stack.account property (#33362)

### Issue # (if applicable)

n/a

### Reason for this change

I stumbled upon this in the documentation and believe it was just a copy-paste error from the Stack.region property
### Description of changes

fix doc to be clear that it's about account-agnostic templates

### Describe any new or updated permissions being added

none


### Description of how you validated changes

n/a

### 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)

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

Author: markusmiliats

packages/aws-cdk-lib/core/lib/stack.ts

@@ -297,9 +297,9 @@ export class Stack extends Construct implements ITaggable {
    * check that it is a concrete value an not an unresolved token. If this
    * value is an unresolved token (`Token.isUnresolved(stack.account)` returns
    * `true`), this implies that the user wishes that this stack will synthesize
-   * into a **account-agnostic template**. In this case, your code should either
+   * into an **account-agnostic template**. In this case, your code should either
    * fail (throw an error, emit a synth error using `Annotations.of(construct).addError()`) or
-   * implement some other region-agnostic behavior.
+   * implement some other account-agnostic behavior.
    */
   public readonly account: string;