Fix the wrong HTTP response status code for duplicate packages (#27480)

fix #27470 
(hope there is nothing missing 😢 )

---------

Co-authored-by: KN4CK3R <admin@oldschoolhack.me>

tests/integration/api_packages_composer_test.go

@@ -112,7 +112,7 @@ func TestPackageComposer(t *testing.T) {
 
 			req = NewRequestWithBody(t, "PUT", uploadURL, bytes.NewReader(content))
 			req = AddBasicAuthHeader(req, user.Name)
-			MakeRequest(t, req, http.StatusBadRequest)
+			MakeRequest(t, req, http.StatusConflict)
 		})
 	})