Arch Linux

Package version: 21.02-1

Description: The python files are installed to the wrong directory, which means python cannot access them:

```
python
Python 3.9.5 (default, May 9 2021, 14:00:28)
[GCC 10.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import pxr
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ModuleNotFoundError: No module named 'pxr'
```

This is presumably caused by the way cmake/ninja is setup to install the files.

Steps to reproduce:

1) Add the following to the bottom of the PKGBUILD:

```
check() {
python3 -c 'import pxr'
}

```

2) Run `extra-x86_64-build .`

3) The package should be built and the check fails with:

```
==> Starting check()...
Traceback (most recent call last):
File "<string>", line 1, in <module>
ModuleNotFoundError: No module named 'pxr'
==> ERROR: A failure occurred in check().
Aborting...
```