gnu: go-github-com-blang-semver: Update version string.

The commit was actually the tag for 3.3.0.

* gnu/packages/golang.scm (go-github-com-blang-semver)[version]: Retag
as 3.3.0.
[source]: Update to use version string.

gnu/packages/golang.scm

@@ -978,28 +978,26 @@ optimized for performance yet simple to use.")
       (license license:expat))))
 
 (define-public go-github-com-blang-semver
-  (let ((commit "60ec3488bfea7cca02b021d106d9911120d25fe9")
-        (revision "0"))
-    (package
-      (name "go-github-com-blang-semver")
-      (version (git-version "0.0.0" revision commit))
-      (source
-       (origin
-         (method git-fetch)
-         (uri (git-reference
-               (url "https://github.com/blang/semver.git")
-               (commit commit)))
-         (file-name (git-file-name name version))
-         (sha256
-          (base32
-           "19pli07y5592g4dyjyj0jq5rn548vc3fz0qg3624vm1j5828p1c2"))))
-      (build-system go-build-system)
-      (arguments
-       '(#:import-path "github.com/blang/semver"))
-      (home-page "https://github.com/blang/semver")
-      (synopsis "Semantic versioning library written in Go")
-      (description "Semver is a library for Semantic versioning written in Go.")
-      (license license:expat))))
+  (package
+    (name "go-github-com-blang-semver")
+    (version "3.3.0")
+    (source
+     (origin
+       (method git-fetch)
+       (uri (git-reference
+             (url "https://github.com/blang/semver.git")
+             (commit (string-append "v" version))))
+       (file-name (git-file-name name version))
+       (sha256
+        (base32
+         "19pli07y5592g4dyjyj0jq5rn548vc3fz0qg3624vm1j5828p1c2"))))
+    (build-system go-build-system)
+    (arguments
+     '(#:import-path "github.com/blang/semver"))
+    (home-page "https://github.com/blang/semver")
+    (synopsis "Semantic versioning library written in Go")
+    (description "Semver is a library for Semantic versioning written in Go.")
+    (license license:expat)))
 
 (define-public go-github-com-emicklei-go-restful
   (let ((commit "89ef8af493ab468a45a42bb0d89a06fccdd2fb22")