### Description of the change
In the act_runner StatefulSet, this allows to mount volumes.
### Benefits
It allows to mount some volumes in any of the two containers, e.g. certificates for a private registry.
### Possible drawbacks
I can't think of any.
### Applicable issues
- Fixes#744
### Checklist
- [X] Parameters are documented in the `values.yaml` and added to the `README.md` using [readme-generator-for-helm](https://github.com/bitnami-labs/readme-generator-for-helm)
- [X] Helm templating unittests are added (required when changing anything in `templates` folder)
Co-authored-by: Xav <grandmou@protonmail.com>
Reviewed-on: https://gitea.com/gitea/helm-chart/pulls/756
Reviewed-by: justusbunsi <justusbunsi@noreply.gitea.com>
Co-authored-by: grandmou <grandmou@noreply.gitea.com>
Co-committed-by: grandmou <grandmou@noreply.gitea.com>
### Description of the change
This addresses 2 bugs regarding configured runner labels:
- `Cannot find: node in PATH` due to a default label that matches the runner host, not the docker-in-docker environment
- After changing the runner config, users have to manually replace the StatefulSet Pod of the runner
### Benefits
- Out-of-the-box functioning node environment
- Auto-updated runner config on changes in values
### Applicable issues
- fixes https://gitea.com/gitea/helm-chart/issues/728
- fixes https://gitea.com/gitea/helm-chart/issues/725
### Additional information
With removing the default labels from `values.yaml`, the act runner defaults will be used for new runners which fixes the "missing node" issue.
I had issues replacing the labels once the Chart defaults were used, so users might have to replace their runner manually if this is an issue.
### Checklist
- [x] Templating unittests are added
Signed-off-by: justusbunsi <sk.bunsenbrenner@gmail.com>
Reviewed-on: https://gitea.com/gitea/helm-chart/pulls/739
Co-authored-by: justusbunsi <sk.bunsenbrenner@gmail.com>
Co-committed-by: justusbunsi <sk.bunsenbrenner@gmail.com>
