ci: add ja to github workflows

Signed-off-by: ktro2828 <kotaro.uetake@tier4.jp>

Author: ktro2828

.github/workflows/build_documentation.yml

@@ -14,6 +14,6 @@ jobs:
       package_name: agents-course
       path_to_docs: agents-course/units/
       additional_args: --not_python_module
-      languages: en zh-CN ru-RU vi es ko
+      languages: en zh-CN ru-RU vi es ko ja
     secrets:
       hf_token: ${{ secrets.HF_DOC_BUILD_PUSH }}

.github/workflows/build_pr_documentation.yml

@@ -17,4 +17,4 @@ jobs:
       package_name: agents-course
       path_to_docs: agents-course/units/
       additional_args: --not_python_module
-      languages: en zh-CN ru-RU vi es ko
+      languages: en zh-CN ru-RU vi es ko ja