Remove test-plan validator workflow. (#224208)

.github/workflows/test-plan-item-validator.yml

@@ -1,29 +0,0 @@
-name: Test Plan Item Validator
-on:
-  issues:
-    types: [edited]
-
-# also edit in ./on-label.yml and ./on-open.yml
-jobs:
-  main:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout Actions
-        if: contains(github.event.issue.labels.*.name, 'testplan-item') || contains(github.event.issue.labels.*.name, 'invalid-testplan-item')
-        uses: actions/checkout@v4
-        with:
-          repository: "microsoft/vscode-github-triage-actions"
-          path: ./actions
-          ref: stable
-      - name: Install Actions
-        if: contains(github.event.issue.labels.*.name, 'testplan-item') || contains(github.event.issue.labels.*.name, 'invalid-testplan-item')
-        run: npm install --production --prefix ./actions
-      - name: Run Test Plan Item Validator
-        if: contains(github.event.issue.labels.*.name, 'testplan-item') || contains(github.event.issue.labels.*.name, 'invalid-testplan-item')
-        uses: ./actions/test-plan-item-validator
-        with:
-          token: ${{secrets.VSCODE_ISSUE_TRIAGE_BOT_PAT}}
-          refLabel: on-testplan
-          label: testplan-item
-          invalidLabel: invalid-testplan-item
-          comment: Invalid test plan item. See errors below and the [test plan item spec](https://github.com/microsoft/vscode/wiki/Writing-Test-Plan-Items) for more information. This comment will go away when the issues are resolved.