Stop hiding the zlib-ng feature

rust-gix-features.spec

@@ -263,6 +263,18 @@ use the "zlib" feature of the "%{crate}" crate.
 %files       -n %{name}+zlib-devel
 %ghost %{crate_instdir}/Cargo.toml
 
+%package     -n %{name}+zlib-ng-devel
+Summary:        %{summary}
+BuildArch:      noarch
+
+%description -n %{name}+zlib-ng-devel %{_description}
+
+This package contains library source intended for building other packages which
+use the "zlib-ng" feature of the "%{crate}" crate.
+
+%files       -n %{name}+zlib-ng-devel
+%ghost %{crate_instdir}/Cargo.toml
+
 %package     -n %{name}+zlib-rust-backend-devel
 Summary:        %{summary}
 BuildArch:      noarch

rust2rpm.toml

@@ -1,5 +1,6 @@
 [package]
 summary = "Integrate various capabilities using compile-time feature flags"
 [features]
-# flate2/zlib-ng is not available in fedora
-hide = ["zlib-ng", "zlib-ng-compat"]
+# The flate2/zlib-ng-compat feature is hidden because not all releases have
+# zlib-ng zlib-compat library; however, we can expose the zlib-ng feature.
+hide = ["zlib-ng-compat"]