BUG: Incorrect path for removing sphinx warning

This will find the exact path of Python's library when we can suppress the duplicate declaration warning

Author: mseng10

.github/workflows/build-test.yml

@@ -287,7 +287,8 @@ jobs:
 
       - name: Remove Duplicate Declaration Warnings
         run: |
-          sed -i "6559d" /opt/hostedtoolcache/Python/3.8.6/x64/lib/python3.8/site-packages/sphinx/domains/cpp.py
+          SITE_PACKAGES_DIR=$(python3 "-c" "from distutils import sysconfig; print(sysconfig.get_python_lib())")
+          sed -i "6559d" ${SITE_PACKAGES_DIR}/sphinx/domains/cpp.py
 
       - name: Download ITK
         run: |