Add Python 3.13.0rc2 to the trial test matrix

.ci/scripts/calculate_jobs.py

@@ -53,7 +53,7 @@ def set_output(key: str, value: str):
  "database": "sqlite",
  "extras": "all",
  }
- for version in ("3.9", "3.10", "3.11", "3.12")
+ for version in ("3.9", "3.10", "3.11", "3.12", "3.13.0rc2")
  )
 
 trial_postgres_tests = [