fix: upgrade @umbraco-cms/backoffice from 14.0.0 to 14.3.1

Snyk has created this PR to upgrade @umbraco-cms/backoffice from 14.0.0 to 14.3.1.

See this package in npm:
@umbraco-cms/backoffice

See this project in Snyk:
https://app.snyk.io/org/jcdcdev/project/156db081-62f3-4d48-9c5f-e95250938ed6?utm_source=github&utm_medium=referral&page=upgrade-pr

Author: snyk-bot