Automatically add retirement label

Makes it easier to filter for such PRs

Author: infinisil

scripts/README.md

@@ -83,7 +83,7 @@ The following sequence tests all code paths:
    PROD=1 scripts/retire.sh infinisil-test-org empty nixpkgs-committers members 'yesterday 1 month ago'
    ```
 
-   Check that it created the PR appropriately.
+   Check that it created the PR appropriately, including assigning the "retirement" label.
    You can undo this step by closing the PR.
 3. Run it again to simulate CI running again later:
    ```bash

scripts/retire.sh

@@ -123,7 +123,7 @@ for login in *; do
       trace git rm "$login"
       trace git commit -m "Automatic retirement of @$login"
       effect git push -f -u origin "$branchName"
-      {
+      prNumber=$({
         echo "This is an automated PR to retire @$login as a Nixpkgs committers due to not using their commit access for 1 year."
         echo ""
         echo "Make a comment with your motivation to keep commit access, otherwise this PR will be merged and implemented in 1 month."
@@ -134,7 +134,14 @@ for login in *; do
          -F "body=@-" \
          -f "head=$ORG:$branchName" \
          -f "base=$mainBranch" \
-         -F "draft=true" >/dev/null
+         -F "draft=true" \
+         --jq .number
+      )
+
+      effect gh api \
+        --method POST \
+        /repos/"$ORG"/"$MEMBER_REPO"/issues/"$prNumber"/labels \
+        -f "labels[]=retirement" >/dev/null
     )
   else
     log "$login is active with $activityCount activities"