SDP-636

28554	Fixed issue file type detection (shell script vs. binary) did not work on some Linux platforms, due to slightly different output from 'file' on shell scripts on different platforms. Type detection logic is now more robust. The test suite will catch this when we add support for Rocky Linux 8. Also corrected a copy/paste error in an error message and enhanced code comments. This is a bug fix to a new, not-yet-released feature.
28424	verify_sdp.sh v5.21.0: Added check that simply named files p4, p4d, p4p, and p4broker in /p4/common/bin are indeed shell scripts, not binaries. Also silenced configurable checks and some other checks that should be skipped if '-skip p4root' is specified. #review @russell_jackson
28553	Fixed issue file type detection (shell script vs. binary) did not work on some Linux platforms, due to slightly different output from 'file' on shell scripts on different platforms. Type detection logic is now more robust. The test suite will catch this when we add support for Rocky Linux 8. Also corrected a copy/paste error in an error message and enhanced code comments. This is a bug fix to a new, not-yet-released feature. #review-28554
28423	verify_sdp.sh v5.21.0: Added check that simply named files p4, p4d, p4p, and p4broker in /p4/common/bin are indeed shell scripts, not binaries. Also silenced configurable checks and some other checks that should be skipped if '-skip p4root' is specified. #review-28424 @russell_jackson