docs: Use intersphinx_registry to keep intersphinx url up to date.

I think one of the difference is it will point toward uproot stable
instead of latest (which is the dev version).

docs/conf.py

@@ -20,6 +20,7 @@
 from pathlib import Path
 
 import jupytext
+from intersphinx_registry import get_intersphinx_mapping
 
 sys.path.insert(0, str(Path('./exts').resolve()))
 
@@ -80,15 +81,17 @@ def setup(app):
 # external links
 xref_links = {"arXiv:1007.1727": ("[1007.1727]", "https://arxiv.org/abs/1007.1727")}
 
-intersphinx_mapping = {
-    'python': ('https://docs.python.org/3', None),
-    'numpy': ('https://numpy.org/doc/stable/', None),
-    'scipy': ('https://docs.scipy.org/doc/scipy/', None),
-    'matplotlib': ('https://matplotlib.org/stable/', None),
-    'iminuit': ('https://iminuit.readthedocs.io/en/stable/', None),
-    'uproot': ('https://uproot.readthedocs.io/en/latest/', None),
-    'jsonpatch': ('https://python-json-patch.readthedocs.io/en/latest/', None),
-}
+intersphinx_mapping = get_intersphinx_mapping(
+    packages={
+        'python',
+        'numpy',
+        'scipy',
+        'matplotlib',
+        'iminuit',
+        'uproot',
+        'jsonpatch',
+    }
+)
 
 # GitHub repo
 issues_github_path = 'scikit-hep/pyhf'

pyproject.toml

@@ -121,6 +121,7 @@ docs = [
     "pydata-sphinx-theme>=0.15.3",
     "nbsphinx!=0.8.8",  # c.f. https://github.com/spatialaudio/nbsphinx/issues/620
     "ipywidgets",
+    "intersphinx_registry",
     "sphinx-issues",
     "sphinx-copybutton>=0.3.2,!=0.5.1",
     "jupyterlite-sphinx>=0.13.1",  # c.f. https://github.com/scikit-hep/pyhf/pull/2458