[release tool]: run nvm gracefully to ensure caretaker uses correct node version for publish branch

The merge tool will currently check out other branches, such as patch, LTS etc. For that the node versions could be different and breaking. This currently results in some inconvenient Yarn install engines error mid-publishing in a way where recovering is rather cumbersome..

We should run `nvm` automatically, gracefully as not everbody might have it. If it fails, we print a warning and proceed running the Yarn install. That one could still fail in such cases, but this is expected then.

Note: We have considered using the Bazel-managed Node version (that would be ideal).. but we cannot let Bazel install the node modules as Bazel itself is actually made available through the `@bazel/bazelisk` package (caretaker might not have the proper Bazel version globally installed; if at all)

Inizia dal flusso di branch-checkout e installazione di Yarn dello strumento di merge, soprattutto nel punto in cui la pubblicazione passa a branch patch o LTS. Verifica come lo strumento gestisce attualmente la configurazione dell’ambiente, quindi verifica che nvm venga tentato in modo controllato, che vengano stampati avvisi quando non è disponibile o quando fallisce e che Yarn install continui a essere eseguito.

Scritto dal modello di indicizzazione a partire dal testo della issue.