ci: doc: bump sphinx from 8.1.3 to 8.2.3 in /doc in the doc-deps group

Bumps the doc-deps group in /doc with 1 update: [sphinx](https://github.com/sphinx-doc/sphinx).

Updates `sphinx` from 8.1.3 to 8.2.3
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/master/CHANGES.rst)
- [Commits](https://github.com/sphinx-doc/sphinx/compare/v8.1.3...v8.2.3)

---
updated-dependencies:
- dependency-name: sphinx
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: doc-deps
...

Signed-off-by: Benjamin Cabé <benjamin@zephyrproject.org>

doc/requirements.in

@@ -1,6 +1,6 @@
 # DOC: used to generate docs
 
-sphinx<8.2.0
+sphinx<8.3.0
 sphinx_rtd_theme~=3.0
 sphinx-tabs
 sphinxcontrib-svg2pdfconverter

doc/requirements.txt

@@ -462,6 +462,10 @@ requests==2.32.3 \
     --hash=sha256:55365417734eb18255590a9ff9eb97e9e1da868d4ccd6402399eaf68af20a760 \
     --hash=sha256:70761cfe03c773ceb22aa2f671b4757976145175cdfca038c02654d061d6dcc6
     # via sphinx
+roman-numerals-py==3.1.0 \
+    --hash=sha256:9da2ad2fb670bcf24e81070ceb3be72f6c11c440d73bd579fbeca1e9f330954c \
+    --hash=sha256:be4bf804f083a4ce001b5eb7e3c0862479d10f94c936f6c4e5f250aa5ff5bd2d
+    # via sphinx
 ruamel-yaml==0.18.10 \
     --hash=sha256:20c86ab29ac2153f80a428e1254a8adf686d3383df04490514ca3b79a362db58 \
     --hash=sha256:30f22513ab2301b3d2b577adc121c6471f28734d3d9728581245f1e76468b4f1
@@ -529,9 +533,9 @@ snowballstemmer==2.2.0 \
     --hash=sha256:09b16deb8547d3412ad7b590689584cd0fe25ec8db3be37788be3810cbf19cb1 \
     --hash=sha256:c8e1716e83cc398ae16824e5572ae04e0d9fc2c6b985fb0f900f5f0c96ecba1a
     # via sphinx
-sphinx==8.1.3 \
-    --hash=sha256:09719015511837b76bf6e03e42eb7595ac8c2e41eeb9c29c5b755c6b677992a2 \
-    --hash=sha256:43c1911eecb0d3e161ad78611bc905d1ad0e523e4ddc202a58a821773dc4c927
+sphinx==8.2.3 \
+    --hash=sha256:398ad29dee7f63a75888314e9424d40f52ce5a6a87ae88e7071e80af296ec348 \
+    --hash=sha256:4405915165f13521d875a8c29c8970800a0141c14cc5416a38feca4ea5d9b9c3
     # via
     #   -r requirements.in
     #   sphinx-autobuild