Update Sphinx tooling requirements

.github/workflows/pull_request.yml

@@ -3,7 +3,7 @@ on: [ pull_request ]
 jobs:
   build:
      name: Build 
-     runs-on: ubuntu-18.04 
+     runs-on: ubuntu-latest
      strategy:
        fail-fast: true
        matrix:

requirements.txt

@@ -1,22 +1,26 @@
-# Support for Read The Docs document generation
-# RTD is supported via sphinx+breathe
-# Sphinx's breathe extension is used to read the Doxygen XML data
-Babel==2.9.1
-Jinja2==2.11.3
-MarkupSafe==0.23
-Pygments==2.7.4
-Sphinx==4.0.2
-alabaster==0.7.9
-argparse==1.2.1
-breathe==4.2.0
-certifi==2022.12.7
-chardet==4.0.0
-docutils==0.17.1
-idna==2.10
-imagesize==0.7.1
-packaging==20.9
-pytz==2016.6.1
-requests==2.25.1
-six==1.10.0
-snowballstemmer==1.2.1
-urllib3==1.26.6
+alabaster==1.0.0
+babel==2.18.0
+breathe==4.36.0
+certifi==2026.4.22
+chardet==7.4.3
+charset-normalizer==3.4.7
+docutils==0.22.4
+idna==3.15
+imagesize==2.0.0
+Jinja2==3.1.6
+MarkupSafe==3.0.3
+packaging==26.2
+Pygments==2.20.0
+pytz==2026.2
+requests==2.34.0
+roman-numerals==4.1.0
+six==1.17.0
+snowballstemmer==3.0.1
+Sphinx==9.1.0
+sphinxcontrib-applehelp==2.0.0
+sphinxcontrib-devhelp==2.0.0
+sphinxcontrib-htmlhelp==2.1.0
+sphinxcontrib-jsmath==1.0.1
+sphinxcontrib-qthelp==2.0.0
+sphinxcontrib-serializinghtml==2.0.0
+urllib3==2.7.0