Bump furo from 2025.9.25 to 2025.12.19 (#9945)

Bumps [furo](https://github.com/pradyunsg/furo) from 2025.9.25 to 2025.12.19.
- [Release notes](https://github.com/pradyunsg/furo/releases)
- [Changelog](https://github.com/pradyunsg/furo/blob/main/docs/changelog.md)
- [Commits](pradyunsg/furo@2025.09.25...2025.12.19)

---
updated-dependencies:
- dependency-name: furo
  dependency-version: 2025.12.19
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

requirements-lock.txt

@@ -137,9 +137,9 @@ docutils==0.21.2 \
     # via
     #   myst-parser
     #   sphinx
-furo==2025.9.25 \
-    --hash=sha256:2937f68e823b8e37b410c972c371bc2b1d88026709534927158e0cb3fac95afe \
-    --hash=sha256:3eac05582768fdbbc2bdfa1cdbcdd5d33cfc8b4bd2051729ff4e026a1d7e0a98
+furo==2025.12.19 \
+    --hash=sha256:188d1f942037d8b37cd3985b955839fea62baa1730087dc29d157677c857e2a7 \
+    --hash=sha256:bb0ead5309f9500130665a26bee87693c41ce4dbdff864dbfb6b0dae4673d24f
     # via -r requirements.txt
 idna==3.10 \
     --hash=sha256:12f65c9b470abda6dc35cf8e63cc574b1c52b11df2c86030af0ac09b01b13ea9 \