To stay current on Composable Storefront and avoid errors on new builds, you must upgrade to Composable Storefront 6 (or later version) and/or Node.js 18 now.
You must be using a current update of Composable Storefront because of the following important note:
Composable Storefront / Spartacus depends on 3rd-party libraries. If a high security issue is discovered with 3rd-party dependencies that are end-of-life (such as Node.js 14), support will be withdrawn from Commerce Cloud with short notice (1-2 weeks). A “high security issue” is an issue that has a vulnerability score (CVSSv3 score) of 7 or higher. For background information on vulnerability scoring, see https://nvd.nist.gov and https://blogs.sap.com/tag/cvss-v3.
This event will be enforced starting in 2024 or because of the event described above (whichever comes first), versions of Composable Storefront that are not current will result in build errors, and you will not be able to deploy new code.