chore: remove packageManager from package.json (#33488)

### Issue # (if applicable)

None

### Reason for this change

I've added `packageManager` section to `package.json` in this [PR](https://github.com/aws/aws-cdk/pull/32719/files#diff-7ae45ad102eab3b6d7e7896acd08c427a9b25b346470d7bc6507b6481575d519) by mistake.

### Description of changes

Remove `packageManager` from `package.json`.

### Describe any new or updated permissions being added

None


### Description of how you validated changes

None

### 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: badmintoncryer

package.json

@@ -179,6 +179,5 @@
   },
   "dependencies": {
     "string-width": "^4.2.3"
-  },
-  "packageManager": "[email protected]+sha1.1959a18351b811cdeedbd484a8f86c3cc3bbaf72"
+  }
 }