exclude slow tests from sharding calc for linux-bionic-py3.7-clang9-test
Fixes #ISSUE_NUMBER
Sharding for linux-bionic-py3.7-clang9 previously included slow test times in the calculation for how long a test takes, causing the sharding to be uneven:
| Duration | Count | Name|
| ----------- | ----------- | ---|
| 11.2m | 221 |linux-bionic-py3.7-clang9 / test (default, 1, 2, linux.2xlarge)|
| 1.1h | 218 | linux-bionic-py3.7-clang9 / test (default, 2, 2, linux.2xlarge)|
Numbers taken from https://hud.pytorch.org/metrics from 04/10/2022 12:20 PM to 04/17/2022 12:20 PM.
The duration of these jobs on this PR are 39m and 38m.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/75918
Approved by: https://github.com/seemethere, https://github.com/janeyx99
