[select] Keep select.is option lists in flash (#20108)

tests/component_tests/select/config/select_is.yaml

@@ -0,0 +1,52 @@
+esphome:
+  name: test
+
+esp8266:
+  board: esp01_1m
+
+select:
+  - platform: template
+    id: mode
+    optimistic: true
+    options: [one, two, three]
+
+button:
+  - platform: template
+    name: A
+    on_press:
+      - if:
+          condition:
+            select.is:
+              id: mode
+              options: [one, two]
+          then:
+            - logger.log: a
+  - platform: template
+    name: B
+    on_press:
+      - if:
+          condition:
+            select.is:
+              id: mode
+              options: [one, two]
+          then:
+            - logger.log: b
+  - platform: template
+    name: C
+    on_press:
+      - if:
+          condition:
+            select.is:
+              id: mode
+              options: three
+          then:
+            - logger.log: c
+      - if:
+          condition:
+            select.is:
+              id: mode
+              lambda: return current == "two";
+          then:
+            - logger.log: d
+
+logger:

tests/component_tests/select/test_select_is.py

@@ -0,0 +1,22 @@
+"""select.is option lists live in shared PROGMEM tables."""
+
+from collections.abc import Callable
+from pathlib import Path
+import re
+
+
+def test_select_is_options_use_shared_progmem_tables(
+    generate_main: Callable[[str | Path], str],
+    component_config_path: Callable[[str], Path],
+) -> None:
+    main_cpp = generate_main(component_config_path("select_is.yaml"))
+
+    tables = re.findall(
+        r"static constexpr const char \* (select_is_options\w*)\[\] PROGMEM = \{([^;]*)\};",
+        main_cpp,
+    )
+    # Two conditions with [one, two] share one table; [three] gets its own
+    assert sorted(body for _, body in tables) == ['"one", "two"', '"three"']
+    one_two = next(name for name, body in tables if body == '"one", "two"')
+    assert main_cpp.count(f", {one_two});") == 2
+    assert "SelectIsCondition<0" in main_cpp