Revert "ci: use corepack in ng-renovate workflow (#2774)"

This reverts commit f7ef306.

Author: alan-agius4

.github/workflows/ng-renovate.yml

@@ -31,10 +31,8 @@ jobs:
       # this step.
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - uses: ./github-actions/npm/checkout-and-setup-node
-      - name: Corepack install and enable
-        run: |
-          npm install corepack -g
-          corepack enable
+      - run: npm install --global pnpm@9.15.6
+        shell: bash
 
       # TODO: Use pnpm/action-setup for pnpm install once pnpm is the packageManager for this repo
       - run: yarn --cwd .github/ng-renovate install --immutable