chore(deps-dev): Bump doccmd from 2026.3.26.2 to 2026.5.6

Bumps [doccmd](https://github.com/adamtheturtle/doccmd) from 2026.3.26.2 to 2026.5.6.
- [Release notes](https://github.com/adamtheturtle/doccmd/releases)
- [Changelog](https://github.com/adamtheturtle/doccmd/blob/main/CHANGELOG.rst)
- [Commits](adamtheturtle/doccmd@2026.03.26.2...2026.05.06)

---
updated-dependencies:
- dependency-name: doccmd
  dependency-version: 2026.5.6
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

pyproject.toml

@@ -59,7 +59,7 @@ optional-dependencies.dev = [
     "deptry==0.25.1",
     "dirty-equals==0.11",
     "doc8==2.0.0",
-    "doccmd==2026.3.26.2",
+    "doccmd==2026.5.6",
     "docker==7.1.0",
     "freezegun==1.5.5",
     "furo==2025.12.19",