Optimize periodic jobs (#100182)
Split existing 4 hour scheduled into two 8 hour ones
And schedule x86 MacOS test every 8 hours and exclude them from leak
checks
Schedule iOS tests every 8 hours and exclude them from leak-checks as
well
Remove IOS metal job, as it is already tested by ARM64 MPS job as well
as x86 and arm64 vanilla jobs, as they never caught any regressions in
last 60 days, based on data from running the following query on RockSet:
```sql
SELECT started_at,
DATE_DIFF(
'MINUTE',
PARSE_TIMESTAMP_ISO8601(started_at),
PARSE_TIMESTAMP_ISO8601(completed_at)
) as duration,
conclusion, name, html_url, torchci_classification
FROM commons.workflow_job
WHERE
workflow_name = 'periodic' and
name like 'ios-12% % build (default, 1, 1, macos-12)' and
url like 'https://api.github.com/repos/pytorch/pytorch/%'
and conclusion = 'failure'
order by started_at desc, run_id;
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/100182
Approved by: https://github.com/PaliC, https://github.com/huydhn
