Create issue_manager.yml

.github/workflows/issue_manager.yml

@@ -0,0 +1,34 @@
+name: Issue Manager
+
+on:
+  issues:
+    types:
+      - labeled
+
+jobs:
+  on_duplicate:
+    if: github.event.label.name == 'duplicate'
+    runs-on: ubuntu-latest
+    permissions:
+      issues: write
+    steps:
+      - name: Add comment
+        uses: peter-evans/create-or-update-comment@5f728c3dae25f329afbe34ee4d08eef25569d79f
+        with:
+          issue-number: ${{ github.event.issue.number }}
+          body: |
+            This issue is a duplicate!
+
+            Please make sure to check for existing issues in this repository before submitting an issue.  
+            If you believe this is a mistake, feel free to reply.
+      - name: Close issue
+        uses: actions/github-script@v6
+        with:
+          script: |
+            github.rest.issues.update({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: context.issue.number,
+              state: "closed",
+              state_reason: "not_planned"
+            });