Update sphinx-issues requirement from <3 to <4 (#214)

Updates the requirements on [sphinx-issues](https://github.com/sloria/sphinx-issues) to permit the latest version.
- [Release notes](https://github.com/sloria/sphinx-issues/releases)
- [Commits](sloria/sphinx-issues@0.1.0...3.0.1)

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

Signed-off-by: dependabot[bot] <[email protected]>

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

Author: dependabot[bot]

setup.cfg

@@ -43,7 +43,7 @@ dev =
     responses==0.21.0
 docs =
     sphinx<7
-    sphinx-issues<3
+    sphinx-issues<4
     furo==2022.6.21
 
 [isort]