Redis: don't synth 'README.rst'. (#6262)

Closes #6260.

Author: tseaver

redis/synth.py

@@ -23,8 +23,9 @@
 gapic = gcp.GAPICGenerator()
 common = gcp.CommonTemplates()
 excludes = [
+    'README.rst',
     'setup.py',
-    'nox.py',
+    'nox*.py',
     'docs/conf.py',
     'docs/index.rst',
 ]