Fix ty failures in new AC temperature-step tests (CI)

ClimateDesc.write_fn is typed as WriteFn (Callable[[Any, dict], ...]),
which only covers the (payload, rep) shape every other capability's
write_fn honors -- calling it through that alias with the climate-only
href/resources args, without first narrowing away the | None, failed
ty two ways: the missing "is not None" check and the extra positional
args past WriteFn's declared arity. Call _climate_write directly
instead, same as test_coordinator_send_command.py and
test_airconditioner_artik051_krac.py already do.

tests/test_airconditioner_capabilities.py

@@ -157,15 +157,21 @@ def test_climate_write_preserves_half_degree_temperature_steps():
     The increment on /temperatures/vs/0 lives inside its items[] entry (the
     same shape every fixture in the corpus uses), not at the resource's top
     level -- a fabricated flat `{"/temperatures/vs/0": {"increment": ...}}`
-    resource would pass a step-reading bug like that silently."""
-    climate_desc = next(e for e in airconditioner.CLIMATE.entities if isinstance(e, ClimateDesc))
-    write = climate_desc.write_fn
+    resource would pass a step-reading bug like that silently.
+
+    Calls _climate_write directly rather than through ClimateDesc.write_fn
+    (as test_climate_write_targets above does): WriteFn only declares the
+    (payload, rep) shape every other write_fn honors, so the type checker
+    rejects a call carrying the climate-only href/resources params through
+    that narrower alias -- same reason test_coordinator_send_command.py and
+    test_airconditioner_artik051_krac.py import the function directly too.
+    """
     resources = _load_device("airconditioner_cac")
-    assert write(("temperature_ocf", 24.5), {}, None, resources) == (
+    assert airconditioner._climate_write(("temperature_ocf", 24.5), {}, None, resources) == (
         ["temperature", "desired", "0"],
         {"temperature": 24.5},
     )
-    assert write(("temperature", 24.5), {}, None, resources) == (
+    assert airconditioner._climate_write(("temperature", 24.5), {}, None, resources) == (
         ["temperatures", "vs", "0"],
         {
             "x.com.samsung.da.items": [
@@ -180,11 +186,9 @@ def test_climate_write_rounds_to_whole_degree_with_no_advertised_increment():
     increment field on /temperatures/vs/0's item -- target_temperature_step
     (climate.py) defaults to 1.0 there, so the write path must match rather
     than pass the raw value through unrounded."""
-    climate_desc = next(e for e in airconditioner.CLIMATE.entities if isinstance(e, ClimateDesc))
-    write = climate_desc.write_fn
     resources = _load_device("airconditioner_artik051_krac_18k")
     assert airconditioner._temperature_step(resources) is None
-    assert write(("temperature", 23.6), {}, None, resources) == (
+    assert airconditioner._climate_write(("temperature", 23.6), {}, None, resources) == (
         ["temperatures", "vs", "0"],
         {
             "x.com.samsung.da.items": [
@@ -199,10 +203,8 @@ def test_climate_write_rejects_non_numeric_temperature():
     build a body with `{"temperature": None}` -- coordinator.py's
     async_send_command logs and drops a write_fn result of None instead of
     POSTing it."""
-    climate_desc = next(e for e in airconditioner.CLIMATE.entities if isinstance(e, ClimateDesc))
-    write = climate_desc.write_fn
-    assert write(("temperature_ocf", "not-a-number"), {}) is None
-    assert write(("temperature", None), {}) is None
+    assert airconditioner._climate_write(("temperature_ocf", "not-a-number"), {}) is None
+    assert airconditioner._climate_write(("temperature", None), {}) is None
 
 
 def test_climate_consumed_hrefs_declared_as_coverage():