Enable testing on newer GCC releases and clean up warnings on them

[penguin359]

In my earlier PR for enabling build testing automation, I stopped at GCC 9.x because newer releases were triggering warnings and would therefore fail the build since -Werror was in effect. This PR adds in those versions and fixes all warnings up through GCC 14.x.

The main issue is the call to strncpy() in the STRNCPY_TERMINATED macro triggers GCC's concerns over a possible non-terminated string even though a quick analysis will show that it is indeed terminated. This warning is present up through at least GCC 14.x. I initially tried to replace the macro with a call to strlcpy() which is a safe version of strncpy(), but that is too new for many systems so I have the warning silenced inside the macro on newer GCC versions. There are no more warnings on any version of GCC tested now.

• Run all matrix combinations even if some fail
• Move to a non-deprecated checkout version
• Added newer GCC versions for test
• Added missing build dependencies
• Use the safe strlcpy() when present
• Make macro safer when strlcpy() is not available
• Disable invalid warning about use of strncpy()

[penguin359]

Hmm, I guess since I am a contributor outside the project modifying the GitHub workflow, it won't automatically run the workflow without approval. I suppose that makes sense, but I was expecting it would just run. In any case, is pretty quick to run the checks once approved.

[penguin359]

After reviewing the build logs from the -Wstringop-truncation warning I tried to silence in my commit ede7ee3258d219cc7460731c4097c509f60615cd, I see that it was actually trying to warn me about the issue with the fixed-sized string string arrays where the source was IFNAMSIZ+1 and the destination was only IFNAMSIZ. That commit should probably be backed out and the warning should go away once issue #108 is fixed. Interestingly, while GCC 10.x seems to detect this with just a -Wall, it looks like GCC 9.x can trigger the warning, but only with ASAN enabled and using the fortified strncpy(). The build logs showing the warning are here:

https://github.com/penguin359/openlldp/actions/runs/10337712563/job/28614883097#step:8:153

[apconole]

Applied, thanks!