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.

runner/harness/http.py

@@ -73,7 +73,7 @@ def http_post(
     `data` is JSON-encoded if content_type='application/json',
     form-encoded if 'application/x-www-form-urlencoded' (the OIDC token endpoint form),
     or sent raw bytes if data is already bytes."""
-    if isinstance(data, (bytes, bytearray)):
+    if isinstance(data, bytes | bytearray):
         body: bytes | None = bytes(data)
     elif content_type == "application/json" and data is not None:
         body = json.dumps(data).encode()
@@ -107,7 +107,7 @@ def http_request(
 ) -> tuple[int, object | None]:
     """Arbitrary-method HTTP (PUT/DELETE/PATCH) for parity tests that mutate. Same shape as
     http_post (returns (status, json_or_None))."""
-    if isinstance(data, (bytes, bytearray)):
+    if isinstance(data, bytes | bytearray):
         body: bytes | None = bytes(data)
     elif content_type == "application/json" and data is not None:
         body = json.dumps(data).encode()
@@ -142,7 +142,7 @@ def post_with_headers(
     """Like http_post but ALSO returns the response headers as a dict — for APIs that hand back an
     auth token in a response header rather than the body (e.g. mattermost login → `Token` header).
     Returns (status, parsed_json_or_None, response_headers). status=0 + {} on transport failure."""
-    if isinstance(data, (bytes, bytearray)):
+    if isinstance(data, bytes | bytearray):
         body: bytes | None = bytes(data)
     elif content_type == "application/json" and data is not None:
         body = json.dumps(data).encode()
@@ -252,13 +252,16 @@ def retry_http_post(
 ) -> tuple[int, object | None]:
     """POST with retry until expect_fn(status, json) is truthy. Defaults to any 2xx."""
     if expect_fn is None:
+
         def expect_fn(s, _j):  # noqa: ARG001
             return 200 <= s < 300
 
     result: list[tuple[int, object | None]] = [(0, None)]
 
     def _check():
-        s, j = http_post(url, data=data, headers=headers, content_type=content_type, timeout=timeout)
+        s, j = http_post(
+            url, data=data, headers=headers, content_type=content_type, timeout=timeout
+        )
         result[0] = (s, j)
         return expect_fn(s, j)