fix: replace deprecated get_astral_location with get_astral_observer (#1482)

* fix: replace deprecated get_astral_location with get_astral_observer (#1481)

HA 2026.7 deprecates homeassistant.helpers.sun.get_astral_location
(removal planned for 2027.7) in favor of get_astral_observer, causing a
deprecation warning in the HA logs.

- Switch SunEvents/SunLightSettings from astral.location.Location to
  astral.Observer, using the astral.sun module functions (which return
  UTC times by default, matching the previous local=False calls).
- Use get_astral_observer in switch.py, with a fallback for HA < 2026.7
  that constructs the Observer directly from the HA config.
- Update tests and the webapp simulator accordingly.

* ci: handle removal of requirements_test_all.txt in HA 2026.8 dev

HA core removed requirements_test_all.txt (home-assistant/core#171530),
which made test_dependencies.py crash with FileNotFoundError and broke
the dev pytest job and the Docker builds. Fall back to
requirements_all.txt, which carries the same per-integration
'# homeassistant.components.x' annotations. Also extend the
aiohasupervisor pin lookup in scripts/setup-dependencies accordingly.

* test: support modern template light config for HA 2026.6+

HA 2026.6 removed the legacy `light: platform: template` YAML format
(home-assistant/core#169615), so setup_lights found no template platform
on HA dev and every test using it failed with IndexError. Detect legacy
support at runtime (PLATFORM_SCHEMA presence) and fall back to the
modern `template:` config format. The group platform is set up before
the template integration in the modern path, because setting up
`template` also sets up the `light` domain, which would make a later
async_setup_component(hass, LIGHT_DOMAIN, ...) a no-op.

tests/test_switch.py

@@ -97,6 +97,7 @@ except ImportError:
     # HA < 2025.8
     from homeassistant.components.template.light import LightTemplate
 
+from homeassistant.components.template import light as template_light
 from homeassistant.config_entries import ConfigEntryState
 from homeassistant.const import (
     ATTR_AREA_ID,
@@ -121,6 +122,10 @@ from homeassistant.util.color import color_temperature_mired_to_kelvin
 
 from tests.common import MockConfigEntry
 
+# HA 2026.6 removed the legacy `light: platform: template` YAML format
+# (home-assistant/core#169615); use the modern `template:` format there.
+LEGACY_TEMPLATE_LIGHTS = hasattr(template_light, "PLATFORM_SCHEMA")
+
 _LOGGER = logging.getLogger(__name__)
 
 SUNRISE = datetime.datetime(
@@ -200,37 +205,65 @@ async def setup_switch(hass, extra_data) -> tuple[MockConfigEntry, AdaptiveSwitc
 async def setup_lights(hass: HomeAssistant, with_group: bool = False):
     """Set up 3 light entities using the 'template' platform."""
     n = 3 if not with_group else 5  # last 2 will be put in a group
-    template_lights = {
-        f"light_{i}": {
-            "unique_id": f"light_{i}",
-            "friendly_name": f"light_{i}",
-            "turn_on": None,
-            "turn_off": None,
-            "set_level": None,
-            "set_temperature": None,
-            "set_color": None,
-        }
-        for i in range(1, n + 1)
+
+    group_platform = {
+        "platform": "group",
+        "entities": ["light.light_4", "light.light_5"],
+        "name": "Light Group",
+        "unique_id": "light_group",
+        "all": "false",
     }
-    template_lights["light_3"]["supports_transition_template"] = True
-    platforms = [{"platform": "template", "lights": template_lights}]
 
-    if with_group:
-        platforms.append(
-            {
-                "platform": "group",
-                "entities": ["light.light_4", "light.light_5"],
-                "name": "Light Group",
-                "unique_id": "light_group",
-                "all": "false",
-            },
+    if LEGACY_TEMPLATE_LIGHTS:
+        template_lights = {
+            f"light_{i}": {
+                "unique_id": f"light_{i}",
+                "friendly_name": f"light_{i}",
+                "turn_on": None,
+                "turn_off": None,
+                "set_level": None,
+                "set_temperature": None,
+                "set_color": None,
+            }
+            for i in range(1, n + 1)
+        }
+        template_lights["light_3"]["supports_transition_template"] = True
+        platforms = [{"platform": "template", "lights": template_lights}]
+        if with_group:
+            platforms.append(group_platform)
+        await async_setup_component(
+            hass,
+            LIGHT_DOMAIN,
+            {LIGHT_DOMAIN: platforms},
+        )
+    else:
+        if with_group:
+            # Setting up `template` below also sets up the `light` domain,
+            # after which `async_setup_component(hass, LIGHT_DOMAIN, ...)`
+            # would be a no-op, so the group platform must be set up first.
+            await async_setup_component(
+                hass,
+                LIGHT_DOMAIN,
+                {LIGHT_DOMAIN: [group_platform]},
+            )
+        modern_lights = [
+            {
+                "name": f"light_{i}",
+                "unique_id": f"light_{i}",
+                "turn_on": None,
+                "turn_off": None,
+                "set_level": None,
+                "set_temperature": None,
+                "set_hs": None,
+            }
+            for i in range(1, n + 1)
+        ]
+        modern_lights[2]["supports_transition"] = "{{ true }}"
+        await async_setup_component(
+            hass,
+            "template",
+            {"template": {"light": modern_lights}},
         )
-
-    await async_setup_component(
-        hass,
-        LIGHT_DOMAIN,
-        {LIGHT_DOMAIN: platforms},
-    )
     await hass.async_block_till_done()
 
     if with_group: