Revert cargo-zigbuild git pin once a release > 0.22.3 ships

.github/actions/build-upstream/action.yml installs cargo-zigbuild from a pinned git commit (7e791b4b) because the fix for the new Rust nightly linker arg --fix-cortex-a53-843419 (rust-cross/cargo-zigbuild#452) is merged but not yet released. Latest release is v0.22.3 (2026-04-26).

Once cargo-zigbuild publishes a release containing that fix, revert the install step back to taiki-e/install-action with tool: cargo-zigbuild.

Releases: https://github.com/rust-cross/cargo-zigbuild/releases