Pane(fix[display_message]): no_expand→-l (literal), remove wrong list_formats

why: -I opens pane stdin input mode (window_pane_start_input), not suppress
     expansion. -l (tmux 3.4, commit 3be36952) is the correct literal flag.
     list_formats mapped to -l with doc "List format variables" — but -l
     suppresses expansion, not lists variables; -a (all_formats) already
     covers listing, making list_formats a wrong duplicate.
what:
- Fix no_expand to emit -l with has_gte_version("3.4") guard + warn on older
- Remove list_formats param from both overloads, implementation, and docstring
- Update no_expand docstring: "-l flag. Requires tmux 3.4+"
- Remove list_formats test case; add no_expand test verifying literal output

Author: tony

src/libtmux/pane.py

@@ -593,7 +593,6 @@ def display_message(
         target_client: str | None = ...,
         delay: int | None = ...,
         notify: bool | None = ...,
-        list_formats: bool | None = ...,
         no_style: bool | None = ...,
     ) -> list[str]: ...
 
@@ -610,7 +609,6 @@ def display_message(
         target_client: str | None = ...,
         delay: int | None = ...,
         notify: bool | None = ...,
-        list_formats: bool | None = ...,
         no_style: bool | None = ...,
     ) -> None: ...
 
@@ -626,7 +624,6 @@ def display_message(
         target_client: str | None = None,
         delay: int | None = None,
         notify: bool | None = None,
-        list_formats: bool | None = None,
         no_style: bool | None = None,
     ) -> list[str] | None:
         """Display message to pane.
@@ -655,7 +652,8 @@ def display_message(
 
             .. versionadded:: 0.45
         no_expand : bool, optional
-            Suppress format expansion (``-I`` flag).
+            Suppress format expansion; output is returned as a literal string
+            (``-l`` flag). Requires tmux 3.4+.
 
             .. versionadded:: 0.45
         target_client : str, optional
@@ -669,10 +667,6 @@ def display_message(
         notify : bool, optional
             Do not wait for input (``-N`` flag).
 
-            .. versionadded:: 0.45
-        list_formats : bool, optional
-            List format variables (``-l`` flag). Requires tmux 3.4+.
-
             .. versionadded:: 0.45
         no_style : bool, optional
             Suppress style output (``-C`` flag). Requires tmux 3.6+.
@@ -700,20 +694,17 @@ def display_message(
             tmux_args += ("-v",)
 
         if no_expand:
-            tmux_args += ("-I",)
-
-        if notify:
-            tmux_args += ("-N",)
-
-        if list_formats:
             if has_gte_version("3.4", tmux_bin=self.server.tmux_bin):
                 tmux_args += ("-l",)
             else:
                 warnings.warn(
-                    "list_formats requires tmux 3.4+, ignoring",
+                    "no_expand requires tmux 3.4+, ignoring",
                     stacklevel=2,
                 )
 
+        if notify:
+            tmux_args += ("-N",)
+
         if no_style:
             if has_gte_version("3.6", tmux_bin=self.server.tmux_bin):
                 tmux_args += ("-C",)

tests/test_pane.py

@@ -677,10 +677,12 @@ class DisplayMessageCase(t.NamedTuple):
         min_tmux_version=None,
     ),
     DisplayMessageCase(
-        test_id="list_formats",
-        cmd="",
-        kwargs={"get_text": True, "list_formats": True},
-        expected_in_output=None,
+        test_id="no_expand",
+        cmd="#{pane_id}",
+        # no_expand=True → -l flag: output should be the literal string, not
+        # the expanded pane id (which would start with %)
+        kwargs={"get_text": True, "no_expand": True},
+        expected_in_output="#{pane_id}",
         min_tmux_version="3.4",
     ),
 ]