Bug 1891375 - Update to sphinx 7.2.6 r=firefox-source-docs-reviewers,ahal DONTBUILD

Differential Revision: https://phabricator.services.mozilla.com/D206585

docs/config.yml

@@ -123,4 +123,4 @@ fatal warnings:
     - "WARNING: '([^']*)' reference target not found:((?!.rst).)*$"
     - "WARNING: Include file '([^']*)' not found or reading it failed"
 
-max_num_warnings: 837
+max_num_warnings: 845

python/sites/docs.txt

@@ -1,5 +1,6 @@
 pth:tools/lint/eslint/
-pypi:Sphinx==7.1.2
+pypi:Sphinx==7.1.2 ; python_version <= '3.8'
+pypi:Sphinx==7.2.6 ; python_version > '3.8'
 pypi:boto3==1.33.5
 pypi:fluent.pygments==1.0
 pypi:livereload==2.6.3

taskcluster/ci/source-test/doc.yml

@@ -4,6 +4,7 @@
 ---
 generate:
     description: Generate the Sphinx documentation
+    use-python: "3.11"
     platform: doc/opt
     treeherder:
         symbol: doc(generate)
@@ -37,6 +38,7 @@ generate:
 
 upload:
     description: Generate and upload the Sphinx documentation
+    use-python: "3.11"
     platform: doc/opt
     attributes:
         code-review: true