gnu: Add rust-dirs-3.

* gnu/packages/crates-io.scm (rust-dirs-3): New variable.
(rust-dirs-2.0): Inherit from above.

gnu/packages/crates-io.scm

@@ -6895,33 +6895,44 @@ on Linux, the Known Folder API on Windows, and the Standard
 Directory guidelines on macOS.")
     (license (list license:expat license:asl2.0))))
 
+(define-public rust-dirs-3
+  (package
+    (name "rust-dirs")
+    (version "3.0.1")
+    (source
+     (origin
+       (method url-fetch)
+       (uri (crate-uri "dirs" version))
+       (file-name (string-append name "-" version ".tar.gz"))
+       (sha256
+        (base32 "1zxrb3anxsh80mnp2il7awccv0s5gvy7djn6gis18nbm0bnraa8l"))))
+    (build-system cargo-build-system)
+    (arguments
+     `(#:cargo-inputs
+       (("rust-dirs-sys" ,rust-dirs-sys-0.3))))
+    (home-page "https://github.com/soc/dirs-rs")
+    (synopsis "Abstractions for standard locations for various platforms")
+    (description
+     "This package is a tiny low-level library that provides platform-specific
+standard locations of directories for config, cache and other data.")
+    (license (list license:expat license:asl2.0))))
+
 (define-public rust-dirs-2.0
   (package
+    (inherit rust-dirs-3)
     (name "rust-dirs")
     (version "2.0.2")
     (source
      (origin
        (method url-fetch)
        (uri (crate-uri "dirs" version))
-        (file-name
+       (file-name (string-append name "-" version ".tar.gz"))
-          (string-append name "-" version ".tar.gz"))
        (sha256
-         (base32
+        (base32 "1qymhyq7w7wlf1dirq6gsnabdyzg6yi2yyxkx6c4ldlkbjdaibhk"))))
-          "1qymhyq7w7wlf1dirq6gsnabdyzg6yi2yyxkx6c4ldlkbjdaibhk"))))
     (arguments
      `(#:cargo-inputs
        (("rust-cfg-if" ,rust-cfg-if-0.1)
-        ("rust-dirs-sys" ,rust-dirs-sys-0.3))))
+        ("rust-dirs-sys" ,rust-dirs-sys-0.3))))))
-    (build-system cargo-build-system)
-    (home-page "https://github.com/soc/dirs-rs")
-    (synopsis "Abstractions for standard locations for various platforms")
-    (description
-     "This package provides a tiny low-level library that provides
-platform-specific standard locations of directories for config, cache and other
-data on Linux, Windows, macOS and Redox by leveraging the mechanisms defined by
-the XDG base/user directory specifications on Linux, the Known Folder API on
-Windows, and the Standard Directory guidelines on macOS.")
-    (license (list license:expat license:asl2.0))))
 
 (define-public rust-dirs-1.0
   (package