fix: sets the method to POST in reRunWorkflow fetch request.

This was not set and defaulted to a GET, causing the request to
fail.

Signed-off-by: Ciprianna Engel <ciprianna.engel@wpengine.com>

plugins/cloudbuild/src/api/CloudbuildClient.ts

@@ -34,6 +34,7 @@ export class CloudbuildClient implements CloudbuildApi {
         options.projectId,
       )}/builds/${encodeURIComponent(options.runId)}:retry`,
       {
+        method: 'POST',
         headers: new Headers({
           Accept: '*/*',
           Authorization: `Bearer ${await this.getToken()}`,