BUG: Plotting broken for spherical meshes (maybe more)

[JDBetteridge]

Describe the bug
There seems to have been some regression plotting functions on spherical meshes

Steps to Reproduce
Steps to reproduce the behavior:

from firedrake import *
from firedrake.pyplot import tripcolor
import matplotlib.pyplot as plt

mesh = UnitIcosahedralMesh(3)
V = FunctionSpace(V, "CG", 1)
f = Function(V)
tripcolor(f) # error here!
plt.show(f)

Expected behavior
I see a plot!

Error message
I was running in an interactive terminal so my traceback doesn't have line numbers.

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "petsc4py/PETSc/Log.pyx", line 188, in petsc4py.PETSc.Log.EventDecorator.decorator.wrapped_func
  File "petsc4py/PETSc/Log.pyx", line 189, in petsc4py.PETSc.Log.EventDecorator.decorator.wrapped_func
  File "/home/jack/Documents/firedrake/firedrake/src/firedrake/firedrake/pyplot/mpl.py", line 274, in tripcolor
    return _plot_2d_field("tripcolor", function, *args, complex_component=complex_component, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/jack/Documents/firedrake/firedrake/src/firedrake/firedrake/pyplot/mpl.py", line 219, in _plot_2d_field
    triangulation = function_plotter.triangulation
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'FunctionPlotter' object has no attribute 'triangulation'

The same happens for UnitCubedSphereMesh too.

If I replace Function with Constant(0) I get a different error message:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "petsc4py/PETSc/Log.pyx", line 188, in petsc4py.PETSc.Log.EventDecorator.decorator.wrapped_func
  File "petsc4py/PETSc/Log.pyx", line 189, in petsc4py.PETSc.Log.EventDecorator.decorator.wrapped_func
  File "/home/jack/Documents/firedrake/firedrake/src/firedrake/firedrake/pyplot/mpl.py", line 274, in tripcolor
    return _plot_2d_field("tripcolor", function, *args, complex_component=complex_component, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/jack/Documents/firedrake/firedrake/src/firedrake/firedrake/pyplot/mpl.py", line 219, in _plot_2d_field
    triangulation = function_plotter.triangulation
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'FunctionPlotter' object has no attribute 'triangulation'

I'm 90% sure this used to work as this MFE was based off a previous script I was using!

Environment:

• OS: Arch Linux
• Python version: 3.12
• Output of firedrake-status:

$ firedrake-status
/home/jack/Documents/firedrake/firedrake/bin/firedrake-status:4: DeprecationWarning: pkg_resources is deprecated as an API. See https://setuptools.pypa.io/en/latest/pkg_resources.html
 __import__('pkg_resources').require('firedrake==0.13.0+6189.gf2a0b1256')
Firedrake Configuration:
   package_manager: False
   minimal_petsc: False
   mpicc: /opt/mpich/bin/mpicc
   mpicxx: /opt/mpich/bin/mpicxx
   mpif90: /opt/mpich/bin/mpif90
   mpiexec: /opt/mpich/bin/mpiexec
   disable_ssh: False
   honour_petsc_dir: True
   with_parmetis: False
   slepc: False
   packages: ['git+ssh://github.com/firedrakeproject/gusto.git@main#egg=gusto', 'ngsPETSc']
   honour_pythonpath: False
   opencascade: False
   tinyasm: False
   torch: False
   petsc_int_type: int32
   cache_dir: /home/jack/Documents/firedrake/firedrake/.cache
   complex: False
   remove_build_files: False
   with_blas: None
   netgen: True
   jax: False
Additions:
   None
Environment:
   PYTHONPATH: None
   PETSC_ARCH: None
   PETSC_DIR: /opt/petsc/firedrake/full-opt
Unable to retrieve git information from .pytest_cache.
Status of components:
---------------------------------------------------------------------------
|Package             |Branch                        |Revision  |Modified  |
---------------------------------------------------------------------------
|FInAT               |master                        |e72e533   |False     |
|PyOP2               |master                        |b84b7708  |False     |
|fiat                |master                        |78fc962   |False     |
|firedrake           |master                        |5e0c48f32 |False     |
|gusto               |JDBetteridge/testing_tests    |e20ef0bc  |False     |
|gusto-docs          |JDBetteridge/keep_alive       |7cea67f   |False     |
|h5py                |firedrake                     |db2ab02f  |False     |
|libsupermesh        |master                        |c07de13   |False     |
|loopy               |main                          |d9876d83  |False     |
|pyadjoint           |master                        |19f8718   |False     |
|pytest-mpi          |main                          |f2566a1   |False     |
|tsfc                |master                        |9f42f95   |False     |
|ufl                 |master                        |c1a8afb1  |False     |
---------------------------------------------------------------------------

• Any relevant environment variables or modifications [eg: PYOP2_DEBUG=1]

Additional Info
matplotlib==3.9.0
triplot works for plotting just the mesh and gives the expected outcome.