Update sphinx-issues requirement from <4 to <5

Updates the requirements on [sphinx-issues](https://github.com/sloria/sphinx-issues) to permit the latest version.
- [Commits](sloria/sphinx-issues@0.1.0...4.0.0)

---
updated-dependencies:
- dependency-name: sphinx-issues
  dependency-type: direct:development
...

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

Author: dependabot[bot]

setup.cfg

@@ -45,7 +45,7 @@ dev =
     responses==0.24.1
 docs =
     sphinx<8
-    sphinx-issues<4
+    sphinx-issues<5
     furo==2023.9.10
 
 [isort]