Enable more linters, and remove mal-functioned milestoned issue action.

Signed-off-by: Xun Jiang <blackpiglet@gmail.com>

.github/workflows/milestoned-issues.yml

@@ -1,18 +0,0 @@
-name: Add issues with a milestone to the milestone's board
-
-on:
-  issues:
-    types: [milestoned]
-
-jobs:
-  automate-project-columns:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: alex-page/github-project-automation-plus@v0.3.0
-        with:
-          # Do NOT add PRs to the board, as that's duplication. Their corresponding issue should be on the board.
-          if: ${{ !github.event.issue.pull_request }}
-          project: "${{ github.event.issue.milestone.title }}"
-          column: "To Do"
-          repo-token: ${{ secrets.GH_TOKEN }}
-