add gcc-toolchain as dependancy for intel

nonfree/intel-compilers.scm

@@ -118,6 +118,8 @@
 
        ("cpio" ,cpio)
        ("rpm" ,rpm)))
+    (propagated-inputs
+     `(("gcc-toolchain" ,gcc-toolchain-9)))
 
     ;; 32-bit libraries are not installed.
     (supported-systems '("x86_64-linux"))