Log a new "timer expired" event to Scuba in file_based_local_timer (#85861)
Summary: The "kill worker process" event was logged to Scuba only when the worker process was really reaped. We want to add a new event "timer expired", no matter the worker process will be reaped or not. This will help collect data before we enable the JustKnob to kill the worker process on timeout.
Test Plan:
### Unit Test
```
buck test mode/dev-nosan //caffe2/test/distributed/elastic/agent/server/test:local_agent_test
```
```
Test Session: https://www.internalfb.com/intern/testinfra/testrun/7318349508929624
RE: reSessionID-ea464c43-54e7-44f2-942b-14ea8aa98c74 Up: 10.5 KiB Down: 1.1 MiB
Jobs completed: 100. Time elapsed: 3206.9s. Cache hits: 91%. Commands: 11 (cached: 10, remote: 1, local: 0)
Tests finished: Pass 55. Fail 0. Fatal 0. Skip 0. 0 builds failed
```
--------
```
buck test mode/dev-nosan //caffe2/test/distributed/elastic/agent/server/test/fb:local_agent_fb_internal_test
```
```
Test Session: https://www.internalfb.com/intern/testinfra/testrun/6473924579130483
RE: reSessionID-231a47b7-a43d-4c0f-9f73-64713ffcbbd3 Up: 5.7 MiB Down: 1.9 GiB
Jobs completed: 182156. Time elapsed: 282.4s. Cache hits: 99%. Commands: 72112 (cached: 72107, remote: 1, local: 4)
Tests finished: Pass 2. Fail 0. Fatal 0. Skip 0. 0 builds failed
```
Differential Revision: D39903376
Pull Request resolved: https://github.com/pytorch/pytorch/pull/85861
Approved by: https://github.com/d4l3k