Update GitHub Actions script in bounty workflow

The commit upgrades the 'github-script' action to version 7 and modifies the method for creating issue comments. This change accommodates updates in the 'github-script' action and aligns with newer API usage for creating issue comments.

.github/workflows/bounty.yml

@@ -17,12 +17,12 @@ jobs:
         run: echo "::set-output name=content::$(cat docs/bounty-footer.md)"
 
       - name: Append Footer to Issue
-        uses: actions/github-script@v3
+        uses: actions/github-script@v7
         with:
           github-token: ${{secrets.GITHUB_TOKEN}}
           script: |
             const issueComment = `${{ steps.footer.outputs.content }}`;
-            github.issues.createComment({
+            github.rest.issues.createComment({
               issue_number: context.issue.number,
               owner: context.repo.owner,
               repo: context.repo.name,