Deprecation warnings with SASS 1.87.0

Problem/Motivation

Compiling the stylesheets in a subtheme or in the Bootstrap5 Main theme produces a number of deprecation warnings indicating that in particular the variable declarations and imports will not be supported in future releases of SASS and need to be migrated.

Steps to reproduce

Compile the stylesheets using SASS 1.87.0 or newer

Proposed resolution

Follow the guidelines and conversion tools described in: info and automated migrator

Remaining tasks

N/A

User interface changes

N/A

API changes

N/A

Data model changes

N/A