pants: switch to faster rust-based python-inference parser

Fixes for this were backported to pants 2.18.3, so we can now benefit
from this massive performance boost for pants.

Author: cognifloyd

pants.toml

@@ -177,9 +177,6 @@ unowned_dependency_behavior = "ignore"
 # file that uses it. So, without manually disambiguating the dep in the BUILD file,
 # importing tests.unit.base in st2common/tests/unit will get a dep on st2common/tests/unit/base.py
 ambiguity_resolution = "by_source_root"
-# https://www.pantsbuild.org/v2.17/docs/reference-python-infer#use_rust_parser
-# This should be much faster, but is giving a lot of "more than one target owns this module" warnings.
-use_rust_parser = false
 
 [setup-py-generation]
 # when building the package (with `pants package ::`), pants will,