build(deps): bump sphinx from 4.5.0 to 5.3.0 in /mobile/docs

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 4.5.0 to 5.3.0.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/master/CHANGES)
- [Commits](sphinx-doc/sphinx@v4.5.0...v5.3.0)

---
updated-dependencies:
- dependency-name: sphinx
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

mobile/docs/requirements.txt

@@ -170,9 +170,9 @@ six==1.16.0 \
 snowballstemmer==2.2.0 \
     --hash=sha256:c8e1716e83cc398ae16824e5572ae04e0d9fc2c6b985fb0f900f5f0c96ecba1a \
     --hash=sha256:09b16deb8547d3412ad7b590689584cd0fe25ec8db3be37788be3810cbf19cb1
-Sphinx==4.5.0 \
-    --hash=sha256:ebf612653238bcc8f4359627a9b7ce44ede6fdd75d9d30f68255c7383d3a6226 \
-    --hash=sha256:7bf8ca9637a4ee15af412d1a1d9689fec70523a68ca9bb9127c2f3eeb344e2e6
+Sphinx==5.3.0 \
+    --hash=sha256:060ca5c9f7ba57a08a1219e547b269fadf125ae25b06b9fa7f66768efb652d6d \
+    --hash=sha256:51026de0a9ff9fc13c05d74913ad66047e104f56a129ff73e174eb5c3ee794b5
 sphinx-rtd-theme==1.1.1 \
     --hash=sha256:31faa07d3e97c8955637fc3f1423a5ab2c44b74b8cc558a51498c202ce5cbda7 \
     --hash=sha256:6146c845f1e1947b3c3dd4432c28998a1693ccc742b4f9ad7c63129f0757c103