Bugfix gimms lai

[msteckle]

Thank you for contributing to ILAMB-Data. Use this template when submitting a pull request.

🛠 Summary of changes

✨Include a reference to the issue # in this section
Summarize the changes you are making to the repo. Are you fixing a bug? Adding a dataset? Describe what you did in a few sentences or bullet points:

• Fixed bug in time array:

     # numpy array of time bounds
     tb_arr = np.asarray([[cf.DatetimeNoLeap(t.dt.year, t.dt.month, t.dt.day) for t in ds['time']], 
-                         [cf.DatetimeNoLeap(t.dt.year, t.dt.month, t.dt.day) for t in ds['time']]]).T
+                         [cf.DatetimeNoLeap(t.dt.year + (t.dt.month==12), (t.dt.month+1) if t.dt.month < 12 else 1, t.dt.day) for t in ds['time']]]).T
     tb_da = xr.DataArray(tb_arr, dims=('time', 'nv'))
     ds['time_bounds'] = tb_da