fix spelling

Author: ChristopherHX

routers/api/actions/artifactsv4.go

@@ -63,7 +63,7 @@ package actions
 //         }
 //     ]
 // }
-// 2.2. GetSignedArtifactURL get the URL to download the artifact zip file of a specfic artifact
+// 2.2. GetSignedArtifactURL get the URL to download the artifact zip file of a specific artifact
 // Post: /twirp/github.actions.results.api.v1.ArtifactService/GetSignedArtifactURL
 // Request
 // {