Adds apptainer version in the cluster guide docs (#357)

After reporting binding issues on the cluster, this fix mentions the
`apptainer version 1.2.5-1.el7` used in our workflow in the cluster
documentation.

- Bug fix (non-breaking change which fixes an issue)

- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./orbit.sh --format`
- [x] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [x] I have run all the tests with `./orbit.sh --test` and they pass
- [ ] I have updated the changelog and the corresponding version in the
extension's `config/extension.toml` file
- [x] I have added my name to the `CONTRIBUTORS.md` or my name already
exists there

docs/source/deployment/cluster.rst

@@ -43,6 +43,10 @@ For simplicity, we recommend that an SSH connection is set up between the local
 development machine and the cluster. Such a connection will simplify the file transfer and prevent
 the user cluster password from being requested multiple times.
 
+.. attention::
+  The workflow has been tested with ``apptainer version 1.2.5-1.el7``. There have been reported binding issues with
+  previous versions (such as ``apptainer version 1.1.3-1.el7``). Please ensure that you are using the latest version.
+
 Configuring the cluster parameters
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~