[ci skip] Revert "Create workflow to add new PRs to the PR Queue project (#6918)" (#7046)

This reverts commit b8d486cbc4.

.github/workflows/pr-board.yml

@@ -1,42 +0,0 @@
-# This workflow handles adding new PRs to the Paper PR Queue project:
-# https://github.com/orgs/PaperMC/projects/2/views/4
-
-# You can get the project ID via:
-# {
-#  organization(login: "PaperMC") {
-#    projectNext(number: 2) {
-#      id
-#    }
-#  }
-#}
-
-name: PR Queue
-on:
-    pull_request:
-        types: [ opened ]
-
-jobs:
-    addToBoard:
-        runs-on: ubuntu-latest
-        steps:
-            -   name: Generate token
-                id: generate_token
-                uses: tibdex/github-app-token@v1
-                with:
-                    app_id: ${{ secrets.APP_ID }}
-                    private_key: ${{ secrets.APP_PEM }}
-            -   name: Add to board
-                id: add-to-board
-                uses: octokit/graphql-action@v2.x
-                with:
-                    query: |
-                        mutation {
-                            addProjectNextItem(input: {projectId: "PN_kwDOAHQads2-_A", contentId: "${{ github.event.pull_request.node_id }}"}) {
-                                projectNextItem {
-                                    id
-                                }
-                            }
-                        }
-                env:
-                    GITHUB_TOKEN: ${{ steps.generate_token.outputs.token }}
-            -   run: "echo 'created: ${{ steps.add-to-board.outputs.data }}'"