Remove myself (Konrad) from PyPI maintainers

I am de facto no longer an active maintainer for quite some time already.
This update to setup.py makes it represent the status quo.

Author: kgadek

setup.py

@@ -12,8 +12,8 @@
     version="2.6.2",
     author="Vadim Gremyachev",
     author_email="[email protected]",
-    maintainer="Konrad Gądek, Domenico Di Nicola",
-    maintainer_email="[email protected], [email protected]",
+    maintainer="Domenico Di Nicola",
+    maintainer_email="[email protected]",
     description="Microsoft 365 & Microsoft Graph Library for Python",
     long_description=long_description,
     long_description_content_type="text/markdown",