Remove myself as maintainer of R packages (#37859)

* Remove myself as maintainer of R packages
  I will no longer have the time to properly maintain these packages.
* fix flake8 test for import

lib/spack/spack/build_systems/r.py

@@ -7,7 +7,7 @@
 
 import llnl.util.lang as lang
 
-from spack.directives import extends, maintainers
+from spack.directives import extends
 
 from .generic import GenericBuilder, Package
 
@@ -71,8 +71,6 @@ class RPackage(Package):
 
     GenericBuilder = RBuilder
 
-    maintainers("glennpj")
-
     #: This attribute is used in UI queries that need to know the build
     #: system base class
     build_system_class = "RPackage"