Ensure `bazelisk` is available in `semantic-release`.

This creates a stub /usr/local/bin/bazelisk that runs the NPM provided Bazelisk.

Eventually, we will not need this as we will run semantic-release through Bazel.

For now, we must have a bazelisk available for copying the run commands.

It also removes input.node_version, in favour of baking in the NodeJS version, so that we do not need to do a breaking change when semantic-release through Bazel. This is a breaking change and is marked as such in the commit message.