freeipa: Cleanup obsolete patches (#381250)

paths.py is included in freeipa since 4.11.0, along with the rest of
ipaplatform/nixos (https://github.com/freeipa/freeipa/commit/f66160fdc9e000db0191c21c51401256e2805cf4),
so our `cp -r` command has been adding a nested
`ipaplatform/nixos/fedora` directory that isn't used.

ipaplatform.nixos is also present upstream in ipaplatform/setup.py now.

pkgs/os-specific/linux/freeipa/default.nix

···
 }:
 
 let
-  pathsPy = ./paths.py;
-
   pythonInputs = with python3.pkgs; [
     distutils
     six
···
   postPatch = ''
     patchShebangs makeapi makeaci install/ui/util
 
-    substituteInPlace ipaplatform/setup.py \
-      --replace 'ipaplatform.debian' 'ipaplatform.nixos'
-
     substituteInPlace ipasetup.py.in \
       --replace 'int(v)' 'int(v.replace("post", ""))'
 
     substituteInPlace client/ipa-join.c \
       --replace /usr/sbin/ipa-getkeytab $out/bin/ipa-getkeytab
 
-    cp -r ipaplatform/{fedora,nixos}
-    substitute ${pathsPy} ipaplatform/nixos/paths.py \
+    substituteInPlace ipaplatform/nixos/paths.py \
       --subst-var out \
       --subst-var-by bind ${bind.dnsutils} \
       --subst-var-by curl ${curl} \

pkgs/os-specific/linux/freeipa/paths.py

···
-from ipaplatform.fedora.paths import FedoraPathNamespace
-
-class NixOSPathNamespace(FedoraPathNamespace):
-    SBIN_IPA_JOIN = "@out@/bin/ipa-join"
-    IPA_GETCERT = "@out@/bin/ipa-getcert"
-    IPA_RMKEYTAB = "@out@/bin/ipa-rmkeytab"
-    IPA_GETKEYTAB = "@out@/bin/ipa-getkeytab"
-    NSUPDATE = "@bind@/bin/nsupdate"
-    BIN_CURL = "@curl@/bin/curl"
-    KINIT = "@kerberos@/bin/kinit"
-    KDESTROY = "@kerberos@/bin/kdestroy"
-
-paths = NixOSPathNamespace()