gnu: sbcl-rt: Remove Make reference from closure.

* gnu/packages/lisp-check.scm (sbcl-rt)[source]: Delete the 'debian' folder.

This takes the closure size from 209 MiB down to 151 MiB.

gnu/packages/lisp-check.scm

@@ -755,7 +755,13 @@ This is intended to be a successor of Prove.")
                (commit commit)))
          (file-name (git-file-name name version))
          (sha256
-          (base32 "13si2rrxaagbr0bkvg6sqicxxpyshabx6ad6byc9n2ik5ysna69b"))))
+          (base32 "13si2rrxaagbr0bkvg6sqicxxpyshabx6ad6byc9n2ik5ysna69b"))
+         (modules '((guix build utils)))
+         (snippet
+          ;; The useless bundled debian folder drags `make' into the closure.
+          `(begin
+             (delete-file-recursively "debian")
+             #t))))
       (build-system asdf-build-system/sbcl)
       (synopsis "MIT Regression Tester")
       (description