fix: update GitHub Actions versions with proper pinning and comments

- Update actions/checkout to v6.0.1 (8e8c483) with version comment
- Update step-security/harden-runner to v2.13.1 (f4a75cf) with version comment
- Update actions/github-script to v8.0.0 (ed59741) with version comment
- Follow project guidelines for pinning actions to commit SHAs

Signed-off-by: cheese-cakee <farzanaman99@gmail.com>

Author: cheese-cakee

.github/workflows/merge-conflict-bot.yml

@@ -22,17 +22,17 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
         with:
           ref: ${{ github.event.repository.default_branch }}
 
       - name: Harden the runner
-        uses: step-security/harden-runner@20cf305ff2072d973412fa9b1e3a4f227bda3c76
+        uses: step-security/harden-runner@f4a75cfd619ee5ce8d5b864b0d183aff3c69b55a # v2.13.1
         with:
           egress-policy: audit
 
       - name: Check for merge conflicts
-        uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd
+        uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8.0.0
         with:
           script: |
             const path = require('path')