fix: the URLs returned in tag api to point to something that exists (#2998)

Co-authored-by: Thomas Geier <thomas.geier@solidat.de>

src/main/scala/gitbucket/core/api/ApiRef.scala

@@ -28,7 +28,7 @@ object ApiRef {
       url = ApiPath(s"/api/v3/repos/${repositoryName.fullName}/git/${ref.getName}"),
       `object` = ApiRefCommit(
         sha = ref.getObjectId.getName,
-        url = ApiPath(s"/api/v3/repos/${repositoryName.fullName}/git/commits/${ref.getObjectId.getName}"),
+        url = ApiPath(s"/api/v3/repos/${repositoryName.fullName}/commits/${ref.getObjectId.getName}"),
         `type` = "commit"
       )
     )
@@ -40,10 +40,16 @@ object ApiRef {
     ApiRef(
       ref = s"refs/tags/${tagInfo.name}",
       url = ApiPath(s"/api/v3/repos/${repositoryName.fullName}/git/refs/tags/${tagInfo.name}"),
+      //the GH api distinguishes between "releases" and plain git tags
+      //for "releases", the api returns a reference to the release object (with type `tag`)
+      //this would be something like s"/api/v3/repos/${repositoryName.fullName}/git/tags/<hash-of-tag>"
+      //with a hash for the tag, which I do not fully understand
+      //since this is not yet implemented in GB, we always return a link to the plain `commit` object,
+      //which GH does for tags that are not annotated
       `object` = ApiRefCommit(
         sha = tagInfo.objectId,
-        url = ApiPath(s"/api/v3/repos/${repositoryName.fullName}/git/tags/${tagInfo.objectId}"), // TODO This URL is not yet available?
-        `type` = "tag"
+        url = ApiPath(s"/api/v3/repos/${repositoryName.fullName}/commits/${tagInfo.objectId}"),
+        `type` = "commit"
       )
     )
 }

src/test/scala/gitbucket/core/api/ApiIntegrationTest.scala

@@ -156,7 +156,6 @@ class ApiIntegrationTest extends AnyFunSuite {
         val ref = repo.getRef("tags/v1.0")
         assert(ref.getRef == "refs/tags/v1.0")
         assert(ref.getUrl.toString == "http://localhost:19999/api/v3/repos/root/create_status_test/git/refs/tags/v1.0")
-        assert(ref.getObject.getType == "tag")
       }
     }
   }