gnu: Remove rust-gumdrop-derive-0.7.

* gnu/packages/crates-io.scm (rust-gumdrop-derive-0.7): Delete variable.

gnu/packages/crates-io.scm

@@ -24716,25 +24716,6 @@ support.")
     (description "This package provides custom derive support for gumdrop.")
     (license (list license:expat license:asl2.0))))
 
-(define-public rust-gumdrop-derive-0.7
-  (package
-    (inherit rust-gumdrop-derive-0.8)
-    (name "rust-gumdrop-derive")
-    (version "0.7.0")
-    (source (origin
-              (method url-fetch)
-              (uri (crate-uri "gumdrop_derive" version))
-              (file-name (string-append name "-" version ".tar.gz"))
-              (sha256
-               (base32
-                "1mrm1h4n13b3n79d1215jq9q9d6sgcvfzdb8i5mcmds0vvj4qich"))))
-    (arguments
-     `(#:skip-build? #t
-       #:cargo-inputs
-       (("rust-proc-macro2" ,rust-proc-macro2-1)
-        ("rust-quote" ,rust-quote-1)
-        ("rust-syn" ,rust-syn-1))))))
-
 (define-public rust-gzip-header-1
   (package
     (name "rust-gzip-header")