## What changes were proposed in this pull request?
I would like to change
```bash
if hash python2.7 2>/dev/null; then
# Attempt to use Python 2.7, if installed:
DEFAULT_PYTHON="python2.7"
else
DEFAULT_PYTHON="python"
fi
```
to just ```DEFAULT_PYTHON="python"```
I'm not sure if it is a great assumption that python2.7 is used by default, when python points to something else.
## How was this patch tested?
(Please explain how this patch was tested. E.g. unit tests, integration tests, manual tests)
(If this patch involves UI changes, please attach a screenshot; otherwise, remove this)
Author: MechCoder <mks542@nyu.edu>
Closes#14016 from MechCoder/followup.