pypy27: 7.3.9 -> 7.3.11

Also build it with pythonInterpreters.pypy27_prebuilt instead of
python27, to avoid it being broken after #201859 is merged.

Keep in mind that the above change will make this derivation only work
with x86_64-linux for now (since pypy27_prebuilt is only packaged for
that platform). However support for newer platforms can be added later,
and a working package for one platform is better than a broken package
in 4 platforms.

pkgs/development/interpreters/python/default.nix

@@ -247,13 +247,13 @@ in {
     sourceVersion = {
       major = "7";
       minor = "3";
-      patch = "9";
+      patch = "11";
     };
 
-    sha256 = "sha256-ObCXKVb2VIzlgoAZ264SUDwy1svpGivs+I0+QsxSGXs=";
+    sha256 = "sha256-ERevtmgx2k6m852NIIR4enRon9AineC+MB+e2bJVCTw=";
     pythonVersion = "2.7";
     db = db.override { dbmSupport = !stdenv.isDarwin; };
-    python = __splicedPackages.python27;
+    python = __splicedPackages.pythonInterpreters.pypy27_prebuilt;
     inherit passthruFun;
     inherit (darwin) libunwind;
     inherit (darwin.apple_sdk.frameworks) Security;