tools: remove `USE_PYTHON3 = True` from PRESUBMIT.py presubmit now uses python3 only. This is generated by $ rg -l '^USE_PYTHON3 = True' | \ xargs sed -z -i "s/\n*USE_PYTHON3 = True\n*/\n\n\n/" with some more modifications. This also removes run_on_python2, run_on_python3, and skip_shebang_check args. Bug: 1207012 Change-Id: I43ac77120dc2456bc065a41750f1f5ddfd88d9e5 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4576841 Commit-Queue: Takuto Ikuta <[email protected]> Reviewed-by: Bruce Dawson <[email protected]> Auto-Submit: Takuto Ikuta <[email protected]> Cr-Commit-Position: refs/heads/main@{#1152146} NOKEYCHECK=True GitOrigin-RevId: e108f10dfc017ddc158a453b2aa44a5fb7a18674