[Error] Additional env vars that conflict with built-in only overwrite if declared first

[parkerlreed]

Describe the bug
When passing in multiple --env arguments within distrobox enter, and it happens to be one that distrobox already uses (like WAYLAND_DISPLAY or QT_AUTO_SCREEN_SCALE_FACTOR), the value only takes effect if it was first to be declared

To Reproduce

--additional-flags "--env WAYLAND_DISPLAY= --env QT_AUTO_SCREEN_SCALE_FACTOR=1"

Correctly overwrites WAYLAND_DISPLAY but then the Qt variable is reset to 0 later in the command line args.

Likewise

--additional-flags "--env QT_AUTO_SCREEN_SCALE_FACTOR=1 --env WAYLAND_DISPLAY="

Correctly overwrites Qt but then WAYLAND_DISPLAY gets superseded by the later command line args.

Expected behavior
Both to be taken into account

Logs
wayland_first.txt
qt_first.txt

Desktop (please complete the following information):

• Are you using podman, docker or lilipod? Docker
• Which version or podman, docker or lilipod? 27.3.1
• Which version of distrobox? git master
• Which host distribution? Arch Linux
• How did you install distrobox? AUR

[parkerlreed]

Seeing this on another system running the same container with podman as the backend. Seemingly the latest distrobox release/git master changed something around this behavior. (Both args were working before this latest round of updates)