[6.2.1][cherrypick]Add bootstrap option to install without building.#9106

3405691582 wants to merge 1 commit intoswiftlang:release/6.2.1swiftlang/swift-package-manager:release/6.2.1from

3405691582:bootstrap_install_6213405691582/swift-package-manager:bootstrap_install_621Copy head branch name to clipboard