Elements of `StdVectorDouble` in MATLAB returned as `java.lang.Double` instead of `double`

Encountered during review of https://github.com/opensim-org/opensim-core/pull/4039.

This following snippet failed on a Mac arm64 machine running arm64 MATLAB, but was not reproducible on another similar machine.

```
>> table = TimeSeriesTable('my_data.sto');
>> times = table.getIndependentColumn();
>> class(times.get(i))

ans =

    'java.lang.Double'
```