Remove stale TODO
TODO was for which was already fixed.
RELNOTES: None
# https://groups.google.com/forum/?nomobile=true#!topic/bazel-dev/4Ql_7eDcLC0
# We do lose the ability to set -o pipefail.
-# TODO(#7843): integration tests for failure to find python / wrong version
-# found / error while trying to print version
-
FAILURE_HEADER="\
Error occurred while attempting to use the default Python toolchain \
(@bazel_tools//tools/python:autodetecting_toolchain)."
