Use rc_context to save figures

This removes the gap where matplotlib is called upon outside of the
context.

plotnine/_utils/context.py

@@ -24,17 +24,13 @@ class plot_context:
     """
 
     def __init__(self, plot: ggplot, show: bool = False):
-        self.plot = plot
-        self.show = show
-
-    def __enter__(self) -> Self:
-        """
-        Enclose in matplolib & pandas environments
-        """
         import matplotlib as mpl
 
-        self.rc_context = mpl.rc_context(self.plot.theme.rcParams)
+        self.plot = plot
+        self.show = show
 
+        # Contexts
+        self.rc_context = mpl.rc_context(plot.theme.rcParams)
         # Pandas deprecated is_copy, and when we create new dataframes
         # from slices we do not want complaints. We always uses the
         # new frames knowing that they are separate from the original.
@@ -44,6 +40,11 @@ def __enter__(self) -> Self:
             "mode.copy_on_write",
             False,
         )
+
+    def __enter__(self) -> Self:
+        """
+        Enclose in matplolib & pandas environments
+        """
         self.rc_context.__enter__()
         self.pd_option_context.__enter__()
         return self

plotnine/ggplot.py

@@ -672,7 +672,9 @@ def save(
             verbose=verbose,
             **kwargs,
         )
-        sv.figure.savefig(**sv.kwargs)
+
+        with plot_context(self).rc_context:
+            sv.figure.savefig(**sv.kwargs)
 
 
 ggsave = ggplot.save
@@ -780,5 +782,6 @@ def facet_pages(column)
         # Re-add the first element to the iterator, if it was removed
         for plot in plots:
             fig = plot.draw()
-            # Save as a page in the PDF file
-            pdf.savefig(fig, **fig_kwargs)
+            with plot_context(plot).rc_context:
+                # Save as a page in the PDF file
+                pdf.savefig(fig, **fig_kwargs)