Added the feature of auto commenting when a PR is merged

[suhanipaliwal]

Description

I have added auto-comment-on-pr-merge.yml in .github/workflows directory. This file will add the feature of auto commenting when a pr is merged.

Related Issues

[Cite any related issue(s) this pull request addresses. If none, simply state “None”]

• Closes Auto Commenting when a PR is merged #276

Type of PR

• Bug fix
• Feature enhancement
• Documentation update
• Other (specify): _______________

Checklist

• I have gone through the contributing guide
• I have updated my branch and synced it with project main branch before making this PR
• I have performed a self-review of my code
• I have tested the changes thoroughly before submitting this pull request.
• I have provided relevant issue numbers, screenshots, and videos after making the changes.
• I have commented my code, particularly in hard-to-understand areas.

[Anishkagupta04]

Thankyou for your contribution!!

[varshith257]

@suhanipaliwal The comment have to trigger when type is merged. Please fix it and open a another PR. We will assign labels there

#246

Just now merged it and checked that this workflow is flaky