gnu: Remove rust-libz-ng-sys-1.

* gnu/packages/crates-io.scm (rust-libz-ng-sys-1): Delete variable.

gnu/packages/crates-io.scm

@@ -33114,30 +33114,6 @@ known as zlib).")
     (license (list license:asl2.0
                    license:expat))))
 
-(define-public rust-libz-ng-sys-1
-  (package
-    (name "rust-libz-ng-sys")
-    (version "1.1.8")
-    (source (origin
-              (method url-fetch)
-              (uri (crate-uri "libz-ng-sys" version))
-              (file-name (string-append name "-" version ".tar.gz"))
-              (sha256
-               (base32
-                "1wp0aya5hh76h1acspvrrsvq2fl0kyb8dpi6wy0zaswnm6bax6a3"))))
-    (build-system cargo-build-system)
-    (arguments
-     `(#:skip-build? #t
-       #:cargo-inputs
-       (("rust-cmake" ,rust-cmake-0.1)
-        ("rust-libc" ,rust-libc-0.2))))
-    (home-page "https://github.com/rust-lang/libz-sys")
-    (synopsis "Low-level bindings to zlib-ng (libz-ng)")
-    (description
-     "This package provides low-level bindings to zlib-ng (libz-ng), a
-high-performance zlib library.")
-    (license (list license:expat license:asl2.0))))
-
 (define-public rust-lifeguard-0.6
   (package
     (name "rust-lifeguard")