Merge pull request 'gitignore: Remove obsolete or unused rules' (#4004) from kenji/gitignore: Remove obsolete or unused rules into main

Reviewed-on: https://git.clan.lol/clan/clan-core/pulls/4004

.gitignore

@@ -3,7 +3,6 @@
 .hypothesis
 out.log
 .coverage.*
-qubeclan
 pkgs/repro-hook
 testdir
 democlan
@@ -32,13 +31,6 @@ __pycache__
 .ruff_cache
 htmlcov
 
-# flatpak
-.flatpak-builder
-build
-build-dir
-repo
-.env
-
 # node
 node_modules
 dist