* Improve service startup "tests"
* Address intermittent download test failure
* Caused by load exceeding threshold
* Add more missing bad HTTPD config tests
* Allow for newer `libpng` with Docker tests
* Also test more image/file types
* Run tests in parallel in some `GitHub Actions` Workflows
* Except for `macOS` & `Coverage` jobs
* Update `Node.js 16` actions to `Node.js 20` versions
* `actions/upload-artifact`
* `actions/cache`
* Add server `IP:Port` in `CTest` HTTPD logs
* Make `render_speedtest_*` CTest tests require tiles to be downloaded
* Add & use tile download functions for CTest
* Including `check` & `remove` "tests"
* To remove much of the redundant code
* Split up HTTPD0/HTTPD1 downloads in CTest
* Remove Amazon Linux 2/CentOS 7 from CI workflow
* Comment out fedora:rawhide, it's not currently working
* Re-enable CentOS Stream tests