Run "Build examples" workflow at a certain interval

[trombik]

The issue

the CI should run not only when a PR is opened, but also at a certain interval.

The context

the CI runs only when PR is opened. as the development of esp-idf progress, there would be issues in master branch. the CI should run once a week, or once a month, to catch incompatibility with the esp-idf master.

Possible solution

No response

Confirmation

• This report is not a bug report in code, a question, nor a request for drivers.