chore(cli): remove CDK_INTEG_MODE hack

[mrgrain]

This hack was used to support the previous integration test system for the monorepo.
It was never publicly advertised and is not used in our setup anymore.
We are removing the unused code to simplify toolkit code.

Reason for this change

Cleaning up unused code.

Description of changes

Removed the unused code block.

Description of how you validated changes

Searched our repo and public GitHub for any usage. Only comes up in forks of the AWS CDK.

Checklist

• My code adheres to the CONTRIBUTING GUIDE and DESIGN GUIDELINES

---

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

[aws-cdk-automation]

The pull request linter has failed. See the aws-cdk-automation comment below for failure reasons. If you believe this pull request should receive an exemption, please comment and provide a justification.

A comment requesting an exemption should contain the text Exemption Request. Additionally, if clarification is needed add Clarification Request to a comment.

[aws-cdk-automation]

➡️ PR build request submitted to test-main-pipeline ⬅️

A maintainer must now check the pipeline and add the pr-linter/cli-integ-tested label once the pipeline succeeds.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 78.80%. Comparing base (a125c24) to head (02fa094).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #32539      +/-   ##
==========================================
+ Coverage   78.77%   78.80%   +0.03%     
==========================================
  Files         108      108              
  Lines        7163     7159       -4     
  Branches     1320     1319       -1     
==========================================
- Hits         5643     5642       -1     
+ Misses       1335     1332       -3     
  Partials      185      185              

Flag	Coverage Δ
suite.unit	78.80% <ø> (+0.03%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Components	Coverage Δ
packages/aws-cdk	78.80% <ø> (+0.03%)	⬆️

✅ Updated pull request passes all PRLinter validations. Dismissing previous PRLinter review.

[aws-cdk-automation]

AWS CodeBuild CI Report

• CodeBuild project: AutoBuildv2Project1C6BFA3F-wQm2hXv2jqQv
• Commit ID: 02fa094
• Result: SUCCEEDED
• Build Logs (available for 30 days)

Powered by github-codebuild-logs, available on the AWS Serverless Application Repository

[mergify]

Thank you for contributing! Your pull request will be updated from main and then merged automatically (do not update manually, and be sure to allow changes to be pushed to your fork).

[github-actions]

Comments on closed issues and PRs are hard for our team to see.
If you need help, please open a new issue that references this one.