fix: correctly check gitbeaker exception response for 404

Signed-off-by: Cory Steers <cory.steers.gmu9@statefarm.com>

.changeset/tidy-rice-raise.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-scaffolder-backend-module-gitlab': patch
+---
+
+Fixed bug in gitlabRepoPush where it was looking in the wrong place in the exception response from gitbeaker when checking if the branch already exists

plugins/scaffolder-backend-module-gitlab/src/actions/gitlabRepoPush.test.ts

@@ -335,8 +335,10 @@ describe('createGitLabCommit', () => {
   describe('createCommitToBranchThatDoesNotExist', () => {
     it('should create a new branch', async () => {
       mockGitlabClient.Branches.show.mockRejectedValue({
-        response: {
-          statusCode: 404,
+        cause: {
+          response: {
+            status: 404,
+          },
         },
       });
       const input = {

plugins/scaffolder-backend-module-gitlab/src/actions/gitlabRepoPush.ts

@@ -156,7 +156,7 @@ export const createGitlabRepoPushAction = (options: {
         await api.Branches.show(repoID, branchName);
         branchExists = true;
       } catch (e: any) {
-        if (e.response?.statusCode !== 404) {
+        if (e.cause?.response?.status !== 404) {
           throw new InputError(
             `Failed to check status of branch '${branchName}'. Please make sure that branch already exists or Backstage has permissions to create one. ${getErrorMessage(
               e,