glibcLocalesUtf8: init at 2.34

glibcLocalesUtf8 is a trimmed down version of glibcLocales that provides
UTF-8 locale. It is useful to use in derivations that need some UTF-8
lcoale, like unzip in https://github.com/NixOS/nixpkgs/pull/176253.

pkgs/top-level/all-packages.nix

···
   relibc = callPackage ../development/libraries/relibc { };
 
   # Only supported on Linux
-  glibcLocales = if stdenv.hostPlatform.isLinux then callPackage ../development/libraries/glibc/locales.nix { } else null;
+  glibcLocales =
+    if stdenv.hostPlatform.isLinux
+    then callPackage ../development/libraries/glibc/locales.nix { }
+    else null;
+  glibcLocalesUtf8 =
+    if stdenv.hostPlatform.isLinux
+    then callPackage ../development/libraries/glibc/locales.nix { allLocales = false; }
+    else null;
 
   glibcInfo = callPackage ../development/libraries/glibc/info.nix { };