gnu: Remove rust-either-1.6.0.

* gnu/packages/crates-io.scm (rust-either-1.6.0): Remove variable.

Change-Id: I4990955c41738f27478957de50d24ac96abf1229

gnu/packages/crates-io.scm

@@ -23440,24 +23440,6 @@ signing, and verification in pure Rust.")
 @code{Right} is a general purpose sum type with two cases.")
     (license (list license:expat license:asl2.0))))
 
-(define-public rust-either-1.6.0
-  (package
-    (inherit rust-either-1)
-    (name "rust-either")
-    (version "1.6.1")
-    (source
-     (origin
-       (method url-fetch)
-       (uri (crate-uri "either" version))
-       (file-name
-        (string-append name "-" version ".tar.gz"))
-       (sha256
-        (base32
-         "0mwl9vngqf5jvrhmhn9x60kr5hivxyjxbmby2pybncxfqhf4z3g7"))))
-    (arguments
-     `(#:cargo-inputs (("rust-serde" ,rust-serde-1))
-       #:cargo-development-inputs (("rust-serde-json" ,rust-serde-json-1.0.73))))))
-
 (define-public rust-elf-0.0.10
   (package
     (name "rust-elf")