style: repo-wide lint pass — make the lint gate green again

Push builds have been RED on the lint step since ~build 209 from accumulated
formatting drift. This is the mechanical cleanup: ruff format + ruff --fix
(UP038 isinstance unions, SIM105 contextlib.suppress, UP031 f-strings, SIM115
tempfile context manager), shfmt -i 2 -ci, nixpkgs-fmt/statix/deadnix (merged
attrsets, dropped unused lib args), yamllint, and shell quoting fixes in
tests/lasuite-docs/setup_custom_tests.sh. No behaviour changes intended;
lint: PASS, unit tests: 138 passed.

tests/plausible/ops.py

@@ -34,4 +34,7 @@ def pre_backup(domain, meta):
 
 def pre_restore(domain, meta):
     _psql(domain, "DROP TABLE ci_marker;")
-    assert _psql(domain, "SELECT to_regclass('public.ci_marker');") in ("", "NULL"), "drop did not take"
+    assert _psql(domain, "SELECT to_regclass('public.ci_marker');") in (
+        "",
+        "NULL",
+    ), "drop did not take"