Upgrade buck2 toolchain

[bigfootjon]

This bumps the toolchain to the latest versions so I can unify the shim: #1993

Test plan:

CI on the PR passes

[pytorch-bot]

🔗 Helpful Links

🧪 See artifacts and rendered test results at hud.pytorch.org/pr/pytorch/executorch/1996

• 📄 Preview Python docs built from this PR

Note: Links to docs will display an error until the docs builds have been completed.

✅ You can merge normally! (1 Unrelated Failure)

As of commit 3f64590 with merge base 1689ed8 ():

BROKEN TRUNK - The following job failed but were present on the merge base:

👉 Rebase onto the `viable/strict` branch to avoid these failures

• Build ExecuTorch demo apps / test-demo-ios / macos-job (gh)
  RuntimeError: Command bash /Users/runner/work/_temp/exec_script failed with exit code 1

This comment was automatically generated by Dr. CI and updates every 15 minutes.

[huydhn]

For the context, MacOS has the logic https://github.com/pytorch/executorch/blob/main/.ci/scripts/setup-macos.sh#L30-L33 to not download buck every time the job runs by checking if buck binary exists. The fault here is that it doesn't check for the buck version. We could fix this by checking for buck version and if it doesn't match the pinned version, then installing the new version

[facebook-github-bot]

@bigfootjon has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator.

[facebook-github-bot]

@bigfootjon merged this pull request in f4c4ad3.