Update pt2-bug-report.yml (#99928)
<!--
copilot:summary
-->
### <samp>🤖 Generated by Copilot at 9691a66</samp>
Update the `pt2-bug-report.yml` template to use `curl` instead of `wget`, `main` instead of `master`, and `python3` instead of `python`. These changes improve the portability and reliability of the bug report process.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/99928
Approved by: https://github.com/kit1980, https://github.com/msaroufim
