Fix CI job script

- wasn't building the tar.xz file correctly
- the order of some copying was wrong

Everything should build locally following the script provided that godot
is installed and set up.
1 job for master in 1 minute and 11 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
failed #11005
librem5
purism

00:01:11

 
Name Stage Failure
failed
purism Build
load resource: res://icon.png
EditorSettings Save OK!
ERROR: ~List: Condition ' _first != __null ' is true.
At: core/self_list.h:100.
WARNING: cleanup: ObjectDB Instances still exist!
At: core/object.cpp:1989.
Leaked Instance: Object:16674
/bin/bash: line 97: 16515 Segmentation fault (core dumped) godot -v -q --path ./$BUILD_NAME --export "Linux/X11" ../build/$DEB_NAME-$DEB_VERSION/$BUILD_NAME.x64
ERROR: Job failed: exit code 1