ci: assigner: Use ubuntu-22.04 virtual environment

This commit updates the pull request assigner workflow to use the
Ubuntu 22.04 virtual environment.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>

.github/workflows/assigner.yml

@@ -15,7 +15,7 @@ jobs:
  assignment:
  name: Pull Request Assignment
  if: github.event.pull_request.draft == false
- runs-on: ubuntu-20.04
+ runs-on: ubuntu-22.04
 
  steps:
  - name: Install Python dependencies