use numpy.isin for compat with v1/2

[eaton-lab]

Fix NumPy 2 compatibility in graph shared-layout path (replace numpy.in1d with numpy.isin)

This is the behave test failure message:

    Scenario: Render subgraph with shared layout                                   # features/graph-
  visualization.feature:41
      Given a graph and a subgraph                                                 # features/steps/graph-
  visualization.py:91
      Then the subgraph can be rendered with the graph layout                      # features/steps/graph-
  visualization.py:97
        Traceback (most recent call last):
          File "/opt/hostedtoolcache/Python/3.11.14/x64/lib/python3.11/site-packages/behave/model.py", line
  1991, in run
            match.run(runner.context)
          File "/opt/hostedtoolcache/Python/3.11.14/x64/lib/python3.11/site-packages/behave/matchers.py",
  line 105, in run
            self.func(context, *args, **kwargs)
          File "features/steps/graph-visualization.py", line 112, in step_impl
            mark = axes.graph(
                   ^^^^^^^^^^^
          File "/home/runner/work/toyplot/toyplot/toyplot/coordinates.py", line 1834, in graph
            layout = toyplot.layout.graph(a, b, c, olayout=olayout, layout=layout, vcoordinates=vcoordinates)
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
          File "/home/runner/work/toyplot/toyplot/toyplot/layout.py", line 289, in graph
            oindices = numpy.in1d(olayout.vids, vids, assume_unique=True)
                       ^^^^^^^^^^
          File "/opt/hostedtoolcache/Python/3.11.14/x64/lib/python3.11/site-packages/numpy/__init__.py", line
  792, in __getattr__
            raise AttributeError(f"module {__name__!r} has no attribute {attr!r}")
        AttributeError: module 'numpy' has no attribute 'in1d'

      And the figure should match the graph-shared-layout-subgraph reference image # None

    Scenario: Render graph with shared layout                                   # features/graph-
  visualization.feature:46
      Given a graph and a subgraph                                              # features/steps/graph-
  visualization.py:91
      Then the graph can be rendered with the subgraph layout                   # features/steps/graph-
  visualization.py:122
        Traceback (most recent call last):
          File "/opt/hostedtoolcache/Python/3.11.14/x64/lib/python3.11/site-packages/behave/model.py", line
  1991, in run
            match.run(runner.context)
          File "/opt/hostedtoolcache/Python/3.11.14/x64/lib/python3.11/site-packages/behave/matchers.py",
  line 105, in run
            self.func(context, *args, **kwargs)
          File "features/steps/graph-visualization.py", line 137, in step_impl
            mark = axes.graph(
                   ^^^^^^^^^^^
          File "/home/runner/work/toyplot/toyplot/toyplot/coordinates.py", line 1834, in graph
            layout = toyplot.layout.graph(a, b, c, olayout=olayout, layout=layout, vcoordinates=vcoordinates)
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
          File "/home/runner/work/toyplot/toyplot/toyplot/layout.py", line 289, in graph
            oindices = numpy.in1d(olayout.vids, vids, assume_unique=True)
                       ^^^^^^^^^^
          File "/opt/hostedtoolcache/Python/3.11.14/x64/lib/python3.11/site-packages/numpy/__init__.py", line
  792, in __getattr__
            raise AttributeError(f"module {__name__!r} has no attribute {attr!r}")
        AttributeError: module 'numpy' has no attribute 'in1d'

      And the figure should match the graph-shared-layout-graph reference image # None

[coveralls]

coverage: 94.119%. remained the same
when pulling 17154bc on eaton-lab:numpy2-isin
into f71796a on sandialabs:main.

[coveralls]

coverage: 94.119%. remained the same
when pulling 17154bc on eaton-lab:numpy2-isin
into f71796a on sandialabs:main.