HooksMixin(fix[set_hook]): Add deprecation warning for g parameter

why: The g parameter was silently ignored in set_hook(), breaking
backward compatibility. Code calling set_hook(..., g=True) would not
get global behavior.

what:
- Add DeprecationWarning when g parameter is used
- Forward g value to global_ for backward compatibility
- Matches pattern used in OptionsMixin.set_option()

Author: tony

src/libtmux/hooks.py

@@ -136,6 +136,14 @@ def set_hook(
         if scope is DEFAULT_OPTION_SCOPE:
             scope = self.default_hook_scope
 
+        if g:
+            warnings.warn(
+                "g argument is deprecated in favor of global_",
+                category=DeprecationWarning,
+                stacklevel=2,
+            )
+            global_ = g
+
         flags: list[str] = []
 
         if unset is not None and unset: