Update Sphinx version for macOS installer build. (GH-24082)

diff --git a/Mac/BuildScript/build-installer.py b/Mac/BuildScript/build-installer.py
index deafcce4f8128ef9c9f33ad2384ad12757241946..ef64502ab780c790cbc34cdfaec40b5d20512921 100755 (executable)
--- a/Mac/BuildScript/build-installer.py
+++ b/Mac/BuildScript/build-installer.py
@@ -1135,7 +1135,6 @@ def buildPythonDocs():
     if not os.path.exists(htmlDir):
         # Create virtual environment for docs builds with blurb and sphinx
         runCommand('make venv')
-        runCommand('venv/bin/python3 -m pip install -U Sphinx==2.3.1')
         runCommand('make html PYTHON=venv/bin/python')
     os.rename(htmlDir, docdir)
     os.chdir(curDir)