Remove documentation on clip for fill in text

Author: weiji14

pygmt/base_plotting.py

@@ -890,10 +890,7 @@ def text(
             case 'C' to get a convex rectangle.
         fill : str
             Sets the shade or color used for filling the text box [Default is
-            no fill]. Alternatively, use fill='c' to plot the text and then use
-            the text dimensions (and *clearance*) to build clip paths and turn
-            clipping on. This clipping can then be turned off later with clip
-            -C. To not plot the text but activate clipping, use fill='C'
+            no fill].
             instead.
         pen : str
             Sets the pen used to draw a rectangle around the text string