HLines and VLines do not work with categorical axes unless vdim is specified

[CodyKlingler]

ALL software version info

(this library, plus any other relevant software, e.g. bokeh, python, notebook, OS, browser, etc should be added within the dropdown below.)

Software Version Info

hvplot==0.11.1
bokeh==3.6.2

Description of expected behavior and the observed behavior

HLines and VLines do not work with categorical axes unless vdim is specified.

Complete, minimal, self-contained example code that reproduces the issue

hv.Curve(zip([1, 3, 2], ["a", "b", "c"])) * hv.VLines([1.5, 2.5]) # Does not work

d = {"x": [1.5, 2.5], "y": None}
hv.Curve(zip([1, 3, 2], ["a", "b", "c"])) * hv.VLines(d, vdims=["y"]) # works

Stacktrace

ValueError: not enough values to unpack (expected 2, got 1)

Traceback (most recent call last):
  File "C:\Users\my_user\Documents\my_project\.venv\Lib\site-packages\panel\io\handlers.py", line 412, in run
    exec(self._code, module.__dict__)
  File "C:\Users\my_user\Documents\my_project\hv.py", line 17, in <module>
    pn.panel(x).servable()
  File "C:\Users\my_user\Documents\my_project\.venv\Lib\site-packages\panel\viewable.py", line 414, in servable
    self.server_doc(title=title, location=location) # type: ignore
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\my_user\Documents\my_project\.venv\Lib\site-packages\panel\viewable.py", line 1022, in server_doc
    model = self.get_root(doc)
            ^^^^^^^^^^^^^^^^^^
  File "C:\Users\my_user\Documents\my_project\.venv\Lib\site-packages\panel\pane\base.py", line 515, in get_root
    root_view, root = self._get_root_model(doc, comm, preprocess)
                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\my_user\Documents\my_project\.venv\Lib\site-packages\panel\pane\base.py", line 456, in _get_root_model
    root = self.layout._get_model(doc, comm=comm)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\my_user\Documents\my_project\.venv\Lib\site-packages\panel\layout\base.py", line 182, in _get_model
    objects, _ = self._get_objects(model, [], doc, root, comm)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\my_user\Documents\my_project\.venv\Lib\site-packages\panel\layout\base.py", line 164, in _get_objects
    child = pane._get_model(doc, root, model, comm)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\my_user\Documents\my_project\.venv\Lib\site-packages\panel\pane\holoviews.py", line 437, in _get_model
    plot = self._render(doc, comm, root)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\my_user\Documents\my_project\.venv\Lib\site-packages\panel\pane\holoviews.py", line 531, in _render
    return renderer.get_plot(self.object, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\my_user\Documents\my_project\.venv\Lib\site-packages\holoviews\plotting\bokeh\renderer.py", line 68, in get_plot
    plot = super().get_plot(obj, doc, renderer, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\my_user\Documents\my_project\.venv\Lib\site-packages\holoviews\plotting\renderer.py", line 239, in get_plot
    plot.update(init_key)
  File "C:\Users\my_user\Documents\my_project\.venv\Lib\site-packages\holoviews\plotting\plot.py", line 956, in update
    return self.initialize_plot()
           ^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\my_user\Documents\my_project\.venv\Lib\site-packages\holoviews\plotting\bokeh\element.py", line 3428, in initialize_plot
    self._update_ranges(element, ranges)
  File "C:\Users\my_user\Documents\my_project\.venv\Lib\site-packages\holoviews\plotting\bokeh\element.py", line 1328, in _update_ranges
    self._update_main_ranges(element, x_range, y_range, ranges)
  File "C:\Users\my_user\Documents\my_project\.venv\Lib\site-packages\holoviews\plotting\bokeh\element.py", line 1371, in _update_main_ranges
    xfactors, yfactors = self._get_factors(element, ranges)
                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\my_user\Documents\my_project\.venv\Lib\site-packages\holoviews\plotting\bokeh\element.py", line 3379, in _get_factors
    xfs, yfs = sp._get_factors(el, elranges)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\my_user\Documents\my_project\.venv\Lib\site-packages\holoviews\plotting\bokeh\element.py", line 1749, in _get_factors
    xdim, ydim = element.dimensions()[:2]
    ^^^^^^^^^^
ValueError: not enough values to unpack (expected 2, got 1)