chore(template): adding regression info in the bug template (#31057)

### Issue # (if applicable)

Closes .

### Reason for this change

Update bug template for users to inform about the code changes that resulted in breaking changes.

### Description of changes

- Adding checkbox to indicate whether this bug is a regression
- Add option of an input for adding last known CDK version
- Add GH workflow to run when an issue is opened or edit, workflow will add label `potential-regression` on the basis whether checkbox is selected in [issue template or not.](https://github.com/shikha372/aws-cdk/blob/regression_template/.github/ISSUE_TEMPLATE/bug-report.yml)

### Description of how you validated changes

Validated template [here](https://github.com/shikha372/aws-cdk/blob/regression_template/.github/ISSUE_TEMPLATE/bug-report.yml) 

Label : potential-regression (will be created after approval)
Label will removed if this option is unchecked and added if this option is checked.

Verified with sample issue in personal repo [here](https://github.com/shikha372/aws-cdk/actions/runs/10326894628), can be tested on sample [github issue ](shikha372#2 in personal repo.
Result will be seen in [github actions](https://github.com/shikha372/aws-cdk/actions).

Sample issue: shikha372#2
Sample run: https://github.com/shikha372/aws-cdk/actions/runs/10326894628/job/28591182838

### 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: shikha372

Diff for: .github/ISSUE_TEMPLATE/bug-report.yml

@@ -20,6 +20,21 @@ body:
       description: What is the problem? A clear and concise description of the bug.
     validations:
       required: true
+  - type: checkboxes
+    id: regression
+    attributes:
+      label: Regression Issue
+      description:  What is a regression? If it worked in a previous version but doesn’t in the latest version, it’s considered a regression. In this case, please provide specific version number in the report.
+      options:
+        - label: Select this option if this issue appears to be a regression.
+          required: false
+  - type: input
+    id: working-version
+    attributes:
+      label: Last Known Working CDK Version
+      description: Specify the last known CDK version where this code was functioning as expected (if applicable).
+    validations:
+      required: false
   - type: textarea
     id: expected
     attributes:

Diff for: .github/workflows/issue-regression-labeler.yml

@@ -0,0 +1,32 @@
+# Apply potential regression label on issues
+name: issue-regression-label
+on:
+  issues:
+    types: [opened, edited]
+jobs:
+  add-regression-label:
+    runs-on: ubuntu-latest
+    permissions:
+      issues: write
+    steps:
+    - name: Fetch template body
+      id: check_regression
+      uses: actions/github-script@v7
+      env: 
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        TEMPLATE_BODY: ${{ github.event.issue.body }}
+      with:
+        script: |
+          const regressionPattern = /\[x\] Select this option if this issue appears to be a regression\./i;
+          const template = `${process.env.TEMPLATE_BODY}`
+          const match = regressionPattern.test(template);
+          core.setOutput('is_regression', match);
+    - name: Manage regression label
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      run: |
+        if [ "${{ steps.check_regression.outputs.is_regression }}" == "true" ]; then
+          gh issue edit ${{ github.event.issue.number }} --add-label "potential-regression" -R ${{ github.repository }}
+        else
+          gh issue edit ${{ github.event.issue.number }} --remove-label "potential-regression" -R ${{ github.repository }}
+        fi