updated and fix sphinx

Author: arrjon

doc/conf.py

@@ -155,7 +155,7 @@
 
 # Add notebooks prolog to Google Colab and nbviewer
 nbsphinx_prolog = r"""
-{% set docname = 'github/icb-dcm/pyabc/blob/main/doc/' + env.doc2path(env.docname, base=None) %}
+{% set docname = 'github/icb-dcm/pyabc/blob/main/doc/' + env.doc2path(env.docname, base=None) | string %}
 .. raw:: html
 
     <div class="note">

setup.cfg

@@ -110,9 +110,9 @@ autograd =
 examples =
     notebook >= 6.1.4
 doc =
-    sphinx >= 6.2.1
-    nbsphinx >= 0.8.9
-    nbconvert >= 6.5.0
+    sphinx >= 8.1.3
+    nbsphinx >= 0.9.5
+    nbconvert >= 7.16.4
     sphinx-rtd-theme >= 1.2.0
     sphinx-autodoc-typehints >= 1.18.3
     ipython >= 8.4.0