builder! Remove tmux < 3.0 environment variable warning

Remove dead code that warned users about environment variable support
requiring tmux 3.0+. Since tmux 3.2+ is now the minimum version,
environment variables are always supported.

- Remove warning blocks for windows and panes
- Remove unused has_lt_version import

Author: tony

src/tmuxp/workspace/builder.py

@@ -9,7 +9,7 @@
 import typing as t
 
 from libtmux._internal.query_list import ObjectDoesNotExist
-from libtmux.common import has_gte_version, has_lt_version
+from libtmux.common import has_gte_version
 from libtmux.pane import Pane
 from libtmux.server import Server
 from libtmux.session import Session
@@ -406,25 +406,6 @@ def iter_create_windows(
                 pass
 
             environment = panes[0].get("environment", window_config.get("environment"))
-            if environment and has_lt_version("3.0"):
-                # Falling back to use the environment of the first pane for the window
-                # creation is nice but yields misleading error messages.
-                pane_env = panes[0].get("environment")
-                win_env = window_config.get("environment")
-                if pane_env and win_env:
-                    target = "panes and windows"
-                elif pane_env:
-                    target = "panes"
-                else:
-                    target = "windows"
-                logger.warning(
-                    (
-                        "Cannot set environment for new %s. "
-                        "You need tmux 3.0 or newer for this."
-                    ),
-                    target,
-                )
-                environment = None
 
             window = session.new_window(
                 window_name=window_name,
@@ -513,16 +494,6 @@ def get_pane_shell(
                     "environment",
                     window_config.get("environment"),
                 )
-                if environment and has_lt_version("3.0"):
-                    # Just issue a warning when the environment comes from the pane
-                    # configuration as a warning for the window was already issued when
-                    # the window was created.
-                    if pane_config.get("environment"):
-                        logger.warning(
-                            "Cannot set environment for new panes. "
-                            "You need tmux 3.0 or newer for this.",
-                        )
-                    environment = None
 
                 assert pane is not None