Update sphinx-issues requirement from <5.0,>=1.2 to >=1.2,<6.0

pyproject.toml

@@ -47,7 +47,7 @@ docs = [
     "doc8>=0.9,<1.2",  # Ensures clean documentation formatting
     "sphinx>=4,<9",  # The default Python documentation redering engine
     "sphinx-autoapi>=1.8,<4",  # Generates documentation from docstrings
-    "sphinx-issues>=1.2,<5.0",  # Allows references to GitHub issues
+    "sphinx-issues>=1.2,<6.0",  # Allows references to GitHub issues
     "sphinx-rtd-dark-mode>=1.2,<2",  # Allow user to toggle light/dark mode
     "sphinx-rtd-theme>=1,<4",  # Standard Sphinx theme for Read The Docs
 ]