docs(core): fix typo in Stack (#32047)

found a very very small typo.

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

@@ -924,7 +924,7 @@ export class Stack extends Construct implements ITaggable {
   }
 
   /**
-   * Adds an arbitary key-value pair, with information you want to record about the stack.
+   * Adds an arbitrary key-value pair, with information you want to record about the stack.
    * These get translated to the Metadata section of the generated template.
    *
    * @see https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/metadata-section-structure.html