Prevent script creating a preview branch from displaying error-looking messages.

[romaricpascal]

What

Prevent the script creating a preview branch from displaying error-looking messages, which judging by the message happens while lint-staged gets run during the commit.

Why

The logs of the script creating the preview branch show a line starting with a red cross:

✍️ Force commit package
✔ Preparing lint-staged...
✔ Running tasks for staged files...
✖ The following paths are ignored by one of your .gitignore files:
  packages/govuk-frontend/dist
  hint: Use -f if you really want to add them.
  hint: Turn this message off by running
  hint: "git config advice.addIgnoredFile false"
✔ Cleaning up temporary files...

This makes it look like something failed in the process when everything was fine.

Who needs to work on this

Who needs to review this

Done when

• Creating a preview branch no longer shows error-looking messages