Update codebuild-ci.yml to trigger CI on doc changes (#4928)

Author: zoewangg

.github/workflows/codebuild-ci.yml

@@ -1,10 +1,5 @@
 name: AWS CodeBuild CI
 on:
-  pull_request:
-    paths-ignore:
-      - '**.md'
-      - '.all-contributorsrc'
-      - 'docs/**'
   push:
     branches:
       - master
@@ -133,4 +128,4 @@ jobs:
       - name: Run endpoints test
         uses: aws-actions/aws-codebuild-run-build@v1
         with:
-          project-name: aws-sdk-java-v2-endpoints-test
+          project-name: aws-sdk-java-v2-endpoints-test