[ci] Roll pinned nightly toolchain#3074

google-pr-creation-bot wants to merge 1 commit intogoogle:maingoogle/zerocopy:mainfrom

google-pr-creation-bot:roll-pinned-nightly-toolchain-to-nightly-2026-03-01-for-maingoogle-pr-creation-bot/zerocopy:roll-pinned-nightly-toolchain-to-nightly-2026-03-01-for-mainCopy head branch name to clipboard