Build demos sequentially

[hidmic]

Precisely what the title says. beluga_demo_build crashed my OS on build, and I have an i7 and 32GB worth of RAM.

[glpuga]

That's weird. Both my computers have half that RAM and it does not crash with the current setup.

Do notice that the current setup has this to prevent the build from crashing due to memory (which did happen without this in my I9). With this the most I observed during build was about 8GB used.

I did not add sequential to the build process because it's so conservative. If we do use sequential, I recommend we remove the MAKEFLAGS variable from the environment.

[hidmic]

Do notice that the current setup has this to prevent the build from crashing due to memory (which did happen without this in my I9). With this the most I observed during build was about 8GB used.

MAKEFLAGS is indeed set 🤔

[glpuga]

Notice that I force pushed to this MR after squashing main.

[hidmic]

Alternatively, we could provide two build command aliases: the current one, plus another, sequential, for modest computers.