chore: unpin gha in renovate and update link checker workflow

Signed-off-by: Devin Buhl <devin@buhl.casa>

.github/workflows/meta-sync-labels.yaml

@@ -13,10 +13,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
+        uses: actions/checkout@v4
 
       - name: Sync Labels
-        uses: EndBug/label-sync@da00f2c11fdb78e4fae44adac2fdd713778ea3e8 # v2.3.2
+        uses: EndBug/label-sync@v2
         with:
           config-file: .github/labels.yaml
           token: "${{ secrets.GITHUB_TOKEN }}"