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/functional/test_health_check.py

@@ -16,7 +16,5 @@ def test_plausible_root_serves(live_app):
     reliable health probe; the dedicated /api/health endpoint is.
     """
     url = f"https://{live_app}/api/health"
-    status, _ = harness_http.retry_http_get(
-        url, expect_status=(200,), max_wait=60, interval=3
-    )
+    status, _ = harness_http.retry_http_get(url, expect_status=(200,), max_wait=60, interval=3)
     assert status == 200, f"GET {url} HTTP {status}"