Fix context manager tracking stack issue causing random 500 errors

[dgarciabriseno]

This was an upstream issue in sunpy where some context managers like transform_with_sun_center were not thread safe, so multiple requests could interfere with each other in this way.

  File "/home/nonroot/.conda/envs/coordinator/lib/python3.13/site-packages/sunpy/coordinates/screens.py", line 42, in __exit__
    raise RuntimeError(f"Cannot remove {self._context_name} from tracking stack because {removed} is last active.")
RuntimeError: Cannot remove sunpy.coordinates.screens.SphericalScreen from tracking stack because sunpy.coordinates._transformations.transform_with_sun_center is last active.
      INFO   172.17.0.1:36796 - "GET
             /hgs2hpc?lat=13&lon=-35&coord_time=2026-02-01T23%3A57Z&target=2026-
             02-02+15%3A43%3A00 HTTP/1.1" 500