Fix git unsafe repository error on ci test

[buzztaiki]

fixes #983

I set safe.directory to avoid the following error in CI

fatal: unsafe repository ('/__w/rbs/rbs' is owned by someone else)

Cause

Starting with git v2.35.2, it seems to cause an error if the current user and the ownership of the directory are different.

ref https://github.blog/2022-04-12-git-security-vulnerability-announced/

The most effective way to protect against this vulnerability is to upgrade to Git v2.35.2. This version changes Git's behavior when looking for a top-level .git directory to stop when its directory traversal changes ownership from the current user. directory configuration).

According to actions/checkout#760, this problem affects if running GH Action in Docker.

rbs project was using git commands in the test, so it was an error.

[pocke]

Thanks!