build: skip for automated PRs and run only when opened

.github/workflows/check_contributing_guidelines_acceptance.yml

@@ -40,7 +40,7 @@ on:
 
  # Trigger on pull request events:
  pull_request_target:
- types: [opened, edited, synchronize, reopened]
+ types: [opened, reopened]
 
 # Global permissions:
 permissions:
@@ -53,15 +53,18 @@ permissions:
 # Workflow jobs:
 jobs:
 
- # Define a job for checking the contributing guidelines acknowledgment...
+ # Define a job for checking the contributing guidelines acceptance...
  check_acknowledgment:
 
  # Define a display name:
- name: 'Check Contributing Guidelines Acknowledgment'
+ name: 'Check Contributing Guidelines Acceptance'
 
  # Define the type of virtual host machine:
  runs-on: ubuntu-latest
 
+ # Skip this job for PRs opened by the stdlib-bot:
+ if: github.event.pull_request.user.login != 'stdlib-bot'
+
  # Define the sequence of job steps...
  steps:
  # Checkout the repository: