Update milestone workflow: rename and add BornToBeRoot maintainer

Co-authored-by: BornToBeRoot <16019165+BornToBeRoot@users.noreply.github.com>

Author: Copilot

.github/workflows/milestone.yml

@@ -1,4 +1,4 @@
-name: Assign milestone to automated PRs
+name: Assign milestone to PRs
 
 on:
   pull_request_target:
@@ -8,7 +8,7 @@ jobs:
   assign-milestone:
     name: Assign next-release milestone
     runs-on: ubuntu-latest
-    if: contains(fromJSON('["dependabot[bot]", "transifex-integration[bot]", "imgbot[bot]", "Copilot"]'), github.event.pull_request.user.login)
+    if: contains(fromJSON('["dependabot[bot]", "transifex-integration[bot]", "imgbot[bot]", "Copilot", "BornToBeRoot"]'), github.event.pull_request.user.login)
     permissions:
       issues: write
       pull-requests: write