Avoid a Sphinx warning when a Latex package is already added

[adamtheturtle]

I use this extension and another extension which adds ulem. My Sphinx build gives: WARNING: latex package 'ulem' already included.

[SilverRainZ]

Thank you! Can you please update the changelog?

[adamtheturtle]

Thank you for looking @SilverRainZ . I have had a go at that

[SilverRainZ]

Get a error after merge this PR:

  Traceback
  =========
  
      Traceback (most recent call last):
        File "/opt/hostedtoolcache/Python/3.12.11/x64/lib/python3.12/site-packages/sphinx/cmd/build.py", line 414, in build_main
          app = Sphinx(
                ^^^^^^^
        File "/opt/hostedtoolcache/Python/3.12.11/x64/lib/python3.12/site-packages/sphinx/application.py", line 291, in __init__
          self.setup_extension(extension)
        File "/opt/hostedtoolcache/Python/3.12.11/x64/lib/python3.12/site-packages/sphinx/application.py", line 489, in setup_extension
          self.registry.load_extension(self, extname)
        File "/opt/hostedtoolcache/Python/3.12.11/x64/lib/python3.12/site-packages/sphinx/registry.py", line 560, in load_extension
          metadata = setup(app)
                     ^^^^^^^^^^
        File "/home/runner/work/strike/strike/src/sphinxnotes/strike/__init__.py", line 84, in setup
          if not app.has_latex_package(latex_package):
                 ^^^^^^^^^^^^^^^^^^^^^
      AttributeError: 'Sphinx' object has no attribute 'has_latex_package'. Did you mean: 'add_latex_package'?

See also https://github.com/sphinx-notes/strike/actions/runs/18186375432/job/51771395324

[adamtheturtle]

Apologies, I'll submit a fix!