refactor add_conclusions in trymerge.py (#82371)
### Description
There were two very similar functions in trymerge so I tried to refactor so that they was less duplicated code.
### Issue
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### Testing
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Ran `python test_trymerge.py` to test
Pull Request resolved: https://github.com/pytorch/pytorch/pull/82371
Approved by: https://github.com/huydhn
