This was necessary because the latest GitHub "runner" image (20221120.1)
includes incompatible image libs (libjpeg, libpng, and zlib). This
caused `fluid-cmd.exe` to fail with error code -1073741511. For further
information please refer to this GitHub Issue:
https://github.com/actions/runner-images/issues/6627
The previous runner version (20221027.1) did not include these libs
and our build used the internal libs and worked.
The fix is to disable the search for system libs in CMake.
Note: this does not explain *why* these libs are incompatible.
- bug_report.md: template for bug reports
- feature_request.md: template for feature requests
- fltk-build-or-usage-question.md: not really a template [1]
[1] Explain to users that this is the wrong place to ask user
questions and refer them to fltk.general
