meson: Sort input file list (#3550)

so that hyprland builds in a reproducible way
in spite of non-deterministic filesystem readdir order.

See https://reproducible-builds.org/ for why this is good.
This patch was done while working on reproducible builds for openSUSE.

Co-authored-by: Bernhard M. Wiedemann <bernhard+gitcommit lsmod.de>

src/meson.build

@@ -1,4 +1,4 @@
-globber = run_command('find', '.', '-name', '*.cpp', check: true)
+globber = run_command('sh', '-c', 'find . -name "*.cpp" | sort', check: true)
 src = globber.stdout().strip().split('\n')
 
 executable('Hyprland', src,