racket-minimal: init at 6.12.0 (same as racket)

Racket without the bundled packages, such as Mr Racket.

The essential package racket-libs is included, as well as libraries
that live in collections. In particular, raco and the pkg library are
still bundled.

pkgs/development/interpreters/racket/minimal.nix

@@ -0,0 +1,10 @@
+{ racket
+}:
+
+racket.overrideAttrs (oldAttrs: rec {
+  name = "racket-minimal-${oldAttrs.version}";
+  src = oldAttrs.src.override {
+    inherit name;
+    sha256 = "0c565jy2y3gjl5lncd5adjsrj8c24p4i062kphv26ni5q1nn5ip5";
+  };
+})