Gitsync fails to read new credentials when using ESO Github token generator

### Description We use Github for our git repos. To provide access from airflow we use External Secrets Operator to manage this using GithubAccessToken that uses a github app to create the access token. This token only lives for 1 hour maximum. Because of this lifespan, The gitsync container needs to re-read the secret to have the new token. Unfortunately it seems that gitsync doesn't support re-reading the secret while it's running. This causes it to fail the sync, exit and restarts. Thankfully it will restart fine and syncs again. ### Use case/motivation Gitsync project have released a new feature https://github.com/kubernetes/git-sync/pull/976 that allows for reading a file that contains the password and re-read it at each sync loop Env vars are only set at startup time so won't detect a change, therefor the secret will have to be mounted inside the container which I think should allow for accepting token rotations? ### Related issues _No response_ ### Are you willing to submit a PR? - [ ] Yes I am willing to submit a PR! ### Code of Conduct - [x] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)