Prevent enet 1.3.18 from installing its include and static files

[user1-github]

Since updating enet to 1.3.18 a few days ago, it has started installing its include and static files with the game (/include/enet and /lib/static/libenet.a) probably due to the addition of these lines in enet 1.3.18 cmakelists file.

I'll admit that I'm not very experienced with cmake so please check if this is correct, but from what I understand, adding EXCLUDE_FROM_ALL after add_subdirectory(${ENET_SOURCE_DIRECTORY} should prevent enet from installing its files but still make it build and statically link with the game.

Since we use strong hardening flags, I thought it makes sense to switch to -D_FORTIFY_SOURCE=3, which is also more aligned with modern distros. However, note that it requires relatively recent compiler versions from about 2022. So if you're interested in being able to build the game on older compilers, we should probably stay on -D_FORTIFY_SOURCE=2.

[TheAssassin]

Compatibility with Ubuntu 22.04 is absolutely needed. Does this change work with that?

Also, technically, you should split this into two commits. We prefer atomic commits.

[user1-github]

Compatibility with Ubuntu 22.04 is absolutely needed. Does this change work with that?

Also, technically, you should split this into two commits. We prefer atomic commits.

Ok,

I just checked, 22.04 uses GCC 11 which doesn't support D_FORTIFY_SOURCE=3, so we'll have to stay on D_FORTIFY_SOURCE=2.

Is everything correct with the enet change?

[TheAssassin]

Yes, that is exactly how it's done. EXCLUDE_FROM_ALL should have been used there from the beginning, I suppose.

[TheAssassin]

Thanks!