Updating dls_pmaclib dependency version.

Author: Rebecca Williams

Pipfile

@@ -9,6 +9,7 @@ pytest-black = "*"
 pytest-flake8 = "*"
 flake8-isort = "*"
 pytest-mypy = "*"
+sphinx = "==4.3.2"
 sphinx-rtd-theme = "*"
 doc8 = "*"
 mock = "*"