This PR turns --status flag into a slice of strings, allowing to filter by more than one status value.

Primary motivation for this change is to be able to exclude cancelled workflow runs from the success/failure analysis as we are using cancel-in-progress: true workflow setting which results in quite a big number of cancelled jobs that significantly skew reported success/failure rate:

$ gh workflow-stats ... --created ">=2024-09-25"
🏃 Total runs: 32
  ✔ Success: 12 (37.5%)
  ✖ Failure: 10 (31.2%)
  🤔 Others: 10 (31.2%)

$ gh workflow-stats ... --created ">=2024-09-25" -s success,failure
🏃 Total runs: 22
  ✔ Success: 12 (54.5%)
  ✖ Failure: 10 (45.5%)
  🤔 Others: 0 (0.0%)

P.S.

This PR also fixes a bug where using previous status filter implementation did NOT correctly filter all run attempts by status as only the last attempts were filtered while previous run attempts were added to the result set without filtering by status.