Merge pull request #3052 from VWS-Python/dependabot/pip/sphinx-substitution-extensions-2026.6.17

chore(deps-dev): Bump sphinx-substitution-extensions from 2026.1.12 to 2026.6.17

Author: github-actions[bot]

pyproject.toml

@@ -74,7 +74,7 @@ optional-dependencies.dev = [
     "sphinx-copybutton==0.5.2",
     "sphinx-lint==1.0.2",
     "sphinx-pyproject==0.3.0",
-    "sphinx-substitution-extensions==2026.1.12",
+    "sphinx-substitution-extensions==2026.6.17",
     "sphinxcontrib-spelling==8.0.2",
     # ``sphinxcontrib-towncrier`` renders unreleased news fragments
     # into docs/source/unreleased.rst during Sphinx builds.