Mnt: fix a couple of things from codeql

docs/source/conf.py

@@ -108,10 +108,6 @@
 # If true, `todo` and `todoList` produce output, else they produce nothing.
 todo_include_todos = False
 
-
-# The name of the Pygments (syntax highlighting) style to use.
-pygments_style = "sphinx"
-
 default_role = "obj"
 
 nitpicky = True

mpl_gui/__init__.py

@@ -235,7 +235,7 @@ def show_all(self, *, block=None, timeout=None):
         if timeout is None:
             timeout = self._timeout
         self._ensure_all_figures_promoted()
-        show(self.figures, block=self._block, timeout=self._timeout)
+        show(self.figures, block=self._block, timeout=timeout)
 
     # alias to easy pyplot compatibility
     show = show_all
@@ -291,7 +291,8 @@ def close(self, val):
 
         """
         if val == "all":
-            return self.close_all()
+            self.close_all()
+            return
         # or do we want to close _all_ of the figures with a given label / number?
         if isinstance(val, str):
             fig = self.by_label[val]
@@ -311,6 +312,7 @@ def close(self, val):
             _FigureCanvasBase(figure=fig)
         assert fig.canvas.manager is None
         self._fig_to_number.pop(fig, None)
+        return
 
 
 class FigureContext(FigureRegistry):

mpl_gui/_manage_backend.py

@@ -79,10 +79,9 @@ def select_gui_toolkit(newbackend=None):
             except ImportError:
                 continue
 
-        else:
-            # Switching to Agg should always succeed; if it doesn't, let the
-            # exception propagate out.
-            return select_gui_toolkit("agg")
+        # Switching to Agg should always succeed; if it doesn't, let the
+        # exception propagate out.
+        return select_gui_toolkit("agg")
 
     if isinstance(newbackend, str):
         # Backends are implemented as modules, but "inherit" default method