Remove jimschubert from C# technical committee (#6865)

I've not used C# since shortly after my initial contributions to the C#
and asp.net generators, and have not followed the .NET Community closely
for a few years now. As I'm focused on other initiatives I am
removing myself from the C# technical committee so that others may
maintain the generator(s) according to the C# community needs.

Author: jimschubert

README.md

@@ -948,7 +948,7 @@ If you want to join the committee, please kindly apply by sending an email to te
 | Bash              | @frol (2017/07) @bkryza (2017/08) @kenjones-cisco (2017/09)                                                                                                                                                                       |
 | C                 | @zhemant (2018/11) @ityuhui (2019/12) @michelealbano (2020/03)                                                                                                                                                                   |
 | C++               | @ravinikam (2017/07) @stkrwork (2017/07) @etherealjoy (2018/02) @martindelille (2018/03) @muttleyxd (2019/08)                                                                                                                     |
-| C#                | @mandrean (2017/08), @jimschubert (2017/09) [:heart:](https://www.patreon.com/jimschubert) @frankyjuang (2019/09) @shibayan (2020/02)                                                                                             |
+| C#                | @mandrean (2017/08) @frankyjuang (2019/09) @shibayan (2020/02)                                                                                             |
 | Clojure           |                                                                                                                                                                                                                                   |
 | Dart              | @ircecho (2017/07) @swipesight (2018/09) @jaumard (2018/09) @athornz (2019/12) @amondnet (2019/12)                                                                                                        |
 | Eiffel            | @jvelilla (2017/09)                                                                                                                                                                                                               |