php55: remove unmaintained version

Does not receive security updates from upstream

pkgs/development/interpreters/php/default.nix

···
     });
 
 in {
-
-  php55 = generic {
-    version = "5.5.38";
-    sha256 = "0f1y76whg6yx9a18mh97f8yq8lb64ri1f0zfr9la9374nbmq2g27";
-  };
-
   php56 = generic {
     version = "5.6.24";
     sha256 = "1iiqmjgxr10ci69f33fzyhplp06km6ybgqmxr1g142pdqdz628xz";

pkgs/top-level/all-packages.nix

···
 
   phpPackages = php56Packages;
 
-  php55Packages = recurseIntoAttrs (callPackage ./php-packages.nix {
-    php = php55;
-  });
-
   php56Packages = recurseIntoAttrs (callPackage ./php-packages.nix {
     php = php56;
   });
···
   });
 
   inherit (callPackages ../development/interpreters/php { })
-    php55
     php56
     php70;