[data_interfaces] JujuVersion.from_environ() is deprecated since Ops 2.19

Recently I noticed the following warning when using data_interfaces:

```
data_interfaces.py:998: DeprecationWarning: JujuVersion.from_environ() is deprecated, use self.model.juju_version instead
self._jujuversion = JujuVersion.from_environ()
```

In Ops 2.19.0 we added [`Model.juju_version`](https://ops.readthedocs.io/en/latest/reference/ops.html#ops.Model.juju_version) and marked `JujuVersion.from_environ()` as deprecated.

Since data_interfaces requires Ops 2.0.0 or above (in [`PYDEPS`](https://github.com/canonical/data-platform-libs/blob/main/lib/charms/data_platform_libs/v0/data_interfaces.py#L336)), I'm not sure whether it would be possible to drop support for `JujuVersion.from_environ()` in data_interfaces. But I thought it would be useful to ask a couple of questions:

- Is there a minimum Ops version that needs to be supported by data_interfaces?

- If data_interfaces needs to support Ops versions prior to 2.19.0, would it be worth adding conditional logic to avoid the warning in newer Ops versions?