Revert "ci: workflows: check for manifest dnm in the manifest workflow"

This reverts commit 370e0882cb, the
condition is evaluated at workout creation time so this does not work at
all, plus some conditions don't have a label removal logic so pairing
this with the manifest run does not work anyway.

Signed-off-by: Fabio Baltieri <fabiobaltieri@google.com>

.github/workflows/manifest.yml

@@ -53,10 +53,3 @@ jobs:
           verbosity-level: '1'
           labels: 'manifest'
           dnm-labels: 'DNM (manifest)'
-
-      - name: Check for label
-        if: ${{ contains(github.event.*.labels.*.name, 'DNM (manifest)') }}
-        run: |
-          echo "Pull request is labeled as 'DNM (manifest)'."
-          echo "This workflow fails so that the pull request cannot be merged."
-          exit 1

.github/workflows/pr_metadata_check.yml

@@ -20,6 +20,7 @@ jobs:
     steps:
       - name: Check for label
         if: ${{ contains(github.event.*.labels.*.name, 'DNM') ||
+                contains(github.event.*.labels.*.name, 'DNM (manifest)') ||
                 contains(github.event.*.labels.*.name, 'TSC') ||
                 contains(github.event.*.labels.*.name, 'Architecture Review') ||
                 contains(github.event.*.labels.*.name, 'dev-review') }}