chore: fix github actions name and dependencies (#12919)

Github actions for v2 are failing because of a dependency definition on
an incorrect name. See [failures].

Further, the dependency is incorrect. The 'auto-approve' job needs to
run on PRs besides forward merges.

Fix Github action names and remove the incorrect dependency.

[failures]: https:/aws/aws-cdk/actions/runs/547681911

.github/workflows/v2-pull-request.yml

@@ -15,8 +15,7 @@ on:
 
 jobs:
  # Run yarn pkglint on merge forward PRs and commit the results
- checkout:
- name: pkglint
+ pkglint:
  if: contains(github.event.pull_request.labels.*.name, 'pr/forward-merge')
  runs-on: ubuntu-latest
  steps:
@@ -36,9 +35,7 @@ jobs:
 
  # Approve automated PRs
  # Only approve! mergify takes care of the actual merge.
- approve:
- name: auto-approve
- needs: pkglint
+ auto-approve:
  if: >
  github.event.pull_request.user.login == 'aws-cdk-automation'
  && contains(github.event.pull_request.labels.*.name, 'pr/auto-approve')