gnu: Remove rust-zstd-safe-3.

* gnu/packages/crates-io.scm (rust-zstd-safe-3): Delete variable.

gnu/packages/crates-io.scm

@@ -76301,24 +76301,6 @@ library.")
        (("rust-libc" ,rust-libc-0.2)
         ("rust-zstd-sys" ,rust-zstd-sys-1))))))
 
-(define-public rust-zstd-safe-3
-  (package
-    (inherit rust-zstd-safe-4)
-    (name "rust-zstd-safe")
-    (version "3.0.1+zstd.1.4.9")
-    (source
-     (origin
-       (method url-fetch)
-       (uri (crate-uri "zstd-safe" version))
-       (file-name (string-append name "-" version ".tar.gz"))
-       (sha256
-        (base32 "133gassn5zy4vf0hhgsff3gxv1q3nc0bzi3qrqq7n4iqv6ycm1qk"))))
-    (arguments
-     `(#:skip-build? #t
-       #:cargo-inputs
-       (("rust-libc" ,rust-libc-0.2)
-        ("rust-zstd-sys" ,rust-zstd-sys-1))))))
-
 ;; TODO: Unbundle zstd.
 ;; The 'legacy' feature, enabled by default, needs headers which aren't
 ;; installed by default in zstd.