gnu: Remove rust-pretty-hex-0.2.

* gnu/packages/crates-io.scm (rust-pretty-hex-0.2): Delete variable.

gnu/packages/crates-io.scm

@@ -43979,24 +43979,6 @@ (define-public rust-pretty-env-logger-0.3
         ("rust-chrono" ,rust-chrono-0.4)
         ("rust-env-logger" ,rust-env-logger-0.6))))))
 
-(define-public rust-pretty-hex-0.2
-  (package
-    (name "rust-pretty-hex")
-    (version "0.2.1")
-    (source
-     (origin
-       (method url-fetch)
-       (uri (crate-uri "pretty-hex" version))
-       (file-name (string-append name "-" version ".tar.gz"))
-       (sha256
-        (base32 "0c91f9sdwmn3mz2d414dp1xk4iw0k1nsif7lyqvhklzh57arjp5w"))))
-    (build-system cargo-build-system)
-    (arguments `(#:skip-build? #t))
-    (home-page "https://github.com/wolandr/pretty-hex")
-    (synopsis "Pretty hex dump of bytes slice in the common style")
-    (description "This is a Rust library providing pretty hex dump.")
-    (license license:expat)))
-
 (define-public rust-prettytable-rs-0.8
   (package
     (name "rust-prettytable-rs")