fix d2 file perms

[aptalca]

currently the generated d2 file is owned by root and the svg generation fails as a result

$ docker run --rm -v /tmp/d2:/output -e PUID=99 -e PGID=100 ghcr.io/linuxserver/d2-builder:latest synclounge:latest
[migrations] started
[migrations] no migrations found
───────────────────────────────────────

      ██╗     ███████╗██╗ ██████╗
      ██║     ██╔════╝██║██╔═══██╗
      ██║     ███████╗██║██║   ██║
      ██║     ╚════██║██║██║   ██║
      ███████╗███████║██║╚██████╔╝
      ╚══════╝╚══════╝╚═╝ ╚═════╝

   Brought to you by linuxserver.io
───────────────────────────────────────

To support LSIO projects visit:
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───────────────────────────────────────
GID/UID
───────────────────────────────────────

User UID:    99
User GID:    100
───────────────────────────────────────
Version: v0.6.8-ls1
Build-date: 2024-11-18T16:27:39+00:00
───────────────────────────────────────
    
Cloning into '/tmp/synclounge'...
Cloning into '/tmp/baseimage-alpine'...
err: failed to compile ../../../../output/synclounge-latest.d2: open /output/synclounge-latest.svg: permission denied
chmod: cannot access '/output/synclounge-latest.svg': No such file or directory
s6-rc: warning: unable to start service init-d2-output: command exited 1
/run/s6/basedir/scripts/rc.init: warning: s6-rc failed to properly bring all the services up! Check your logs (in /run/uncaught-logs/current if you have in-container logging) for more information.
/run/s6/basedir/scripts/rc.init: fatal: stopping the container.

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[LinuxServer-CI]

I am a bot, here is the pushed image/manifest for this PR:

ghcr.io/linuxserver/lspipepr-d2-builder:v0.6.8-pkg-24b0f078-dev-a8188b8ea4535dc2f6760fc3faeddb8f4a10aedb-pr-2

[LinuxServer-CI]

I am a bot, here is the pushed image/manifest for this PR:

ghcr.io/linuxserver/lspipepr-d2-builder:v0.6.8-pkg-24b0f078-dev-17b7a61a429a59d0fcb70f43c1b5b005306cff16-pr-2