Updating cmake scripts to work with cmake 3.31+

[andrsd]

• maint: bump gtest version to 1.15.2
• maint: updating code coverage script for cmake 3.31+
• maint: reflow in cmake/CodeCoverage
• maint: update cmake doc generating script to work with 3.31+

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 86.33%. Comparing base (7f5d732) to head (801e1b4).
Report is 5 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #671   +/-   ##
=======================================
  Coverage   86.33%   86.33%           
=======================================
  Files         188      188           
  Lines       12751    12751           
=======================================
  Hits        11009    11009           
  Misses       1742     1742           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.