chore: rename label for auto approvals (#18183)

The current label (`pr/auto-approve`) doesn't match the default label that `projen` uses (`auto-approve`). 

Our repository monitoring mechanisms use `pr/auto-approve` to detect stale PR's, while this is OK for the `jsii` and `aws-cdk` repositories, its not for basically all other repo's, since they are managed by projen. 

So we need to change the label our monitoring uses to `auto-approve`, this PR is a preparation for that, so we don't loose monitoring of this repo.  

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: iliapolo

.github/dependabot.yml

@@ -9,5 +9,5 @@ updates:
     schedule:
       interval: "weekly"
     labels:
-      - "pr/auto-approve"
+      - "auto-approve"
     open-pull-requests-limit: 5

.github/workflows/pr-labeler.yml

@@ -13,6 +13,6 @@ jobs:
       pull-requests: write
       issues: write
     steps:
-    - run: gh pr edit ${{ github.event.pull_request.number }} --add-label "pr/auto-approve" -R ${{ github.repository }}
+    - run: gh pr edit ${{ github.event.pull_request.number }} --add-label "auto-approve" -R ${{ github.repository }}
       env:
         GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/yarn-upgrade.yml

@@ -110,7 +110,7 @@ jobs:
           title: 'chore: npm-check-updates && yarn upgrade'
           body: |-
             Ran npm-check-updates and yarn upgrade to keep the `yarn.lock` file up-to-date.
-          labels: contribution/core,dependencies,pr/auto-approve
+          labels: contribution/core,dependencies,auto-approve
           team-reviewers: aws-cdk-team
           # Github prevents further Github actions to be run if the default Github token is used.
           # Instead use a privileged token here, so further GH actions can be triggered on this PR.