Remove deprecated dependency_links config (#2753)

* Move dependency_links to setup.cfg

[options] is not a valid table in pyproject.toml, but it is in setup.cfg: https://setuptools.pypa.io/en/latest/deprecated/dependency_links.html

* Remove setup.cfg

https://github.com/nerfstudio-project/nerfstudio/pull/2753#issuecomment-1893217202

pyproject.toml

@@ -129,12 +129,6 @@ ns-export = "nerfstudio.scripts.exporter:entrypoint"
 ns-dev-test = "nerfstudio.scripts.github.run_actions:entrypoint"
 ns-dev-sync-viser-message-defs = "nerfstudio.scripts.viewer.sync_viser_message_defs:entrypoint"
 
-[options]
-# equivalent to using --extra-index-url with pip, which is needed for specifying the CUDA version torch and torchvision
-dependency_links = [
-    "https://download.pytorch.org/whl/cu118"
-]
-
 [tool.setuptools.packages.find]
 include = ["nerfstudio*"]