Restrict pyparsing version to 2.x.x.
Restrict pyparsing version to 2.x.x.

The autowrap code is not compatible with pyparsing 3.x.x. Fixes #210.

PiperOrigin-RevId: 405526958
Change-Id: I909c1c5205fbe31edac97d14a33fb1950cc1d6a5

deepmind/dm_control