ci: Typo fix

Author: sjinks

.github/workflows/build-docker-image.yml

@@ -15,7 +15,7 @@ jobs:
         uses: actions/github-script@v6
         with:
           script: |
-            github.repos.createDispatchEvent({
+            github.rest.repos.createDispatchEvent({
               owner: 'automattic',
               repo: 'vip-container-images',
               event_type: 'build-mu-plugins',