dev-python/*: remove proxy-maint from metadata.xml

Signed-off-by: Lucio Sauer <watermanpaint@posteo.net>

dev-python/grpc-stubs/metadata.xml

@@ -5,10 +5,6 @@
     <email>watermanpaint@posteo.net</email>
     <name>Lucio Sauer</name>
   </maintainer>
-  <maintainer type="project" proxied="proxy">
-    <email>proxy-maint@gentoo.org</email>
-    <name>Proxy Maintainers</name>
-  </maintainer>
   <upstream>
     <remote-id type="github">shabbyrobe/grpc-stubs</remote-id>
     <remote-id type="pypi">grpc-stubs</remote-id>

dev-python/pytest-mypy-plugins/metadata.xml

@@ -5,10 +5,6 @@
     <email>watermanpaint@posteo.net</email>
     <name>Lucio Sauer</name>
   </maintainer>
-  <maintainer type="project" proxied="proxy">
-    <email>proxy-maint@gentoo.org</email>
-    <name>Proxy Maintainers</name>
-  </maintainer>
   <upstream>
     <changelog>
       https://github.com/typeddjango/pytest-mypy-plugins/blob/master/CHANGELOG.md

dev-python/types-protobuf/metadata.xml

@@ -5,10 +5,6 @@
         <email>watermanpaint@posteo.net</email>
         <name>Lucio Sauer</name>
     </maintainer>
-    <maintainer type="project" proxied="proxy">
-        <email>proxy-maint@gentoo.org</email>
-        <name>Proxy Maintainers</name>
-    </maintainer>
     <upstream>
         <remote-id type="github">python/typeshed</remote-id>
         <remote-id type="pypi">types-protobuf</remote-id>