Update open_rasterio deprecation version number (#5916)

TomNicholas · keewis · web-flow · commit 960010b00119 · 2021-11-02T19:03:58.000+01:00
* update version number

* also update in documentation [skip-ci]

Co-authored-by: Keewis &lt;keewis@posteo.de&gt;
diff --git a/doc/user-guide/io.rst b/doc/user-guide/io.rst
@@ -742,7 +742,7 @@ GeoTIFFs and other gridded raster datasets can be opened using `rasterio`_, if
 rasterio is installed. Here is an example of how to use
 :py:func:`open_rasterio` to read one of rasterio's `test files`_:
 
-.. deprecated:: 0.19.1
+.. deprecated:: 0.20.0
 
         Deprecated in favor of rioxarray.
         For information about transitioning, see:
diff --git a/xarray/backends/rasterio_.py b/xarray/backends/rasterio_.py
@@ -172,7 +172,7 @@ def open_rasterio(
 ):
     """Open a file with rasterio.
 
-    .. deprecated:: 0.19.1
+    .. deprecated:: 0.20.0
 
         Deprecated in favor of rioxarray.
         For information about transitioning, see:
