Use an emptyDir instead of a persistentVolumeClaim for MinIO in the integration tests

[siegfriedweber]

Description

The integration tests fail on an IONOS cluster because MinIO cannot be deployed due to the following error:

failed to provision volume with StorageClass "ionos-enterprise-hdd": rpc error: code = OutOfRange desc = requested size 67108864 must be between 1073741824 and 4398046511104 bytes

A PersistentVolumeClaim with 64 MiB is created which is not supported. Instead of requesting 1 GiB, an emptyDir is now used instead.

Definition of Done Checklist

• Not all of these items are applicable to all PRs, the author should update this template to only leave the boxes in that are relevant
• Please make sure all these things are done and tick the boxes

# Author
- [x] Integration tests passed (for non trivial changes)

# Reviewer
- [ ] Code contains useful comments
- [ ] Code contains useful logging statements
- [ ] (Integration-)Test cases added
- [ ] Documentation added or updated. Follows the [style guide](https://docs.stackable.tech/home/nightly/contributor/docs-style-guide).
- [ ] Changelog updated
- [ ] Cargo.toml only contains references to git tags (not specific commits or branches)

# Acceptance
- [ ] Feature Tracker has been updated
- [ ] Proper release label has been added
- [ ] [Roadmap](https://github.com/orgs/stackabletech/projects/25/views/1) has been updated

[siegfriedweber]

✅ https://ci.stackable.tech/view/02%20Operator%20Tests%20(custom)/job/hbase-operator-it-custom/156/

[sbernauer]

Many thanks for looking at the failures!