gnu: Remove rust-syntex-0.58.

* gnu/packages/crates-io.scm (rust-syntex-0.58): Delete variable.

gnu/packages/crates-io.scm

@@ -61945,32 +61945,6 @@ standard library.")
 intelligence using Sublime Text's grammars.")
     (license license:expat)))
 
-(define-public rust-syntex-0.58
- (package
-   (name "rust-syntex")
-   (version "0.58.1")
-   (source
-    (origin
-      (method url-fetch)
-      (uri (crate-uri "syntex" version))
-      (file-name
-       (string-append name "-" version ".tar.gz"))
-      (sha256
-       (base32
-        "03lgd36cxhc6gzaab0wqvckbhml00s6s73lk34ymf6cklymf7xd8"))))
-   (build-system cargo-build-system)
-   (arguments
-    `(#:skip-build? #t
-      #:cargo-inputs
-      (("rust-syntex-errors" ,rust-syntex-errors-0.58)
-       ("rust-syntex-syntax" ,rust-syntex-syntax-0.58))))
-   (home-page "https://github.com/erickt/rust-syntex")
-   (synopsis "Compile time syntax extension expansion")
-   (description
-    "This package provides a library that enables compile time
-syntax extension expansion.")
-   (license (list license:expat license:asl2.0))))
-
 (define-public rust-syntex-errors-0.58
   (package
     (name "rust-syntex-errors")