MDEV-38546: Automatically label new unlabeled pull requests

 with foundation/corporation/external contribution

The MariaDB server repository uses certain pull request labels as queue markers
 for incoming pull requests as follows:
 - External Contribution: for all external contributions
- MariaDB Corporation: for employees of the MariaDB corporation
- MariaDB Foundation: for the employees of the MariaDB foundation

Right now, when a new pull request is filed, these tags need to be applied
manually.
However a large % of these manual assignments can be automated by checking
if the author is in https://github.com/orgs/MariaDB/teams/staff
or in https://github.com/orgs/MariaDB/teams/developers.

If they are in staff "MariaDB Foundation" is assigned.

if they are not in staff, but are in developers, "MariaDB Foundation" is assigned.

If they are in neither staff not developers, "External Contribution" is assigned.

A github workflow is created to do the assignments. It is being triggered
every day at 2AM. Or it can be triggered manually.

Author: gkodinov

.github/workflows/label_recent_prs.yaml

@@ -0,0 +1,95 @@
+name: Label recent pull requests
+
+on:
+  schedule:
+    - cron: "0 2 * * *" # 02:00 UTC daily
+  workflow_dispatch:    # allow manual runs
+
+permissions:
+  contents: read
+  pull-requests: write
+  issues: write
+
+jobs:
+  label-prs:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Auto-label PRs
+        env:
+          REPO: ${{ github.repository }}
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          set -euo pipefail
+
+          one_week_ago=$(date -u -d '7 days ago' +"%Y-%m-%dT%H:%M:%SZ")
+
+          echo "Checking PRs created after $one_week_ago"
+
+          # List open PRs as JSON
+          gh pr list \
+            --repo "$REPO" \
+            --state open \
+            --limit 200 \
+            --json number,createdAt,labels,author |
+          jq -c '.[]' |
+          while read -r pr; do
+            pr_number=$(echo "$pr" | jq -r '.number')
+            created_at=$(echo "$pr" | jq -r '.createdAt')
+            label_count=$(echo "$pr" | jq '.labels | length')
+            author=$(echo "$pr" | jq -r '.author.login')
+
+            # Only PRs from the last week
+            if [[ "$created_at" < "$one_week_ago" ]]; then
+              continue
+            fi
+
+            # Skip PRs that already have labels
+            #if [[ "$label_count" -ne 0 ]]; then
+            #  continue
+            #fi
+
+            #TODO: remove
+            if [[ "$pr_number" -ne 4536 ]]; then
+              continue
+            fi
+
+            echo "Evaluating PR #$pr_number by $author"
+
+            is_developer=0
+            # Check if author is in the developers team
+            if gh api \
+              -H "Accept: application/vnd.github+json" \
+              "/orgs/MariaDB/teams/developers/members/$author" \
+              --verbose; then
+              echo "Author is in developers team"
+              is_developer=1
+            else
+              echo "Author is not in developers team"
+            fi
+            is_foundation=0
+            # Check if author is in the staff team
+            if gh api \
+              -H "Accept: application/vnd.github+json" \
+              "/orgs/MariaDB/teams/staff/members/$author" \
+              --verbose; then
+              echo "Author is in staff team"
+              is_foundation=1
+            else
+              echo "Author is not in staff team"
+            fi
+
+            label="External Contribution"
+            if [[ "$is_foundation" -ne 0 ]]; then
+              label="MariaDB Foundation"
+            else
+              if [[ "$is_developer" -ne 0 ]]; then
+                label="MariaDB Corporation"
+              fi
+            fi
+
+            echo "Applying label $label"
+            gh issue edit "$pr_number" \
+              --repo "$REPO" \
+              --add-label "$label"
+          done