Revert "maintainer-scripts: fix superfluous 'sh' for Python script"

This reverts commit 9072763f.

maintainer-scripts/crontab

 16  0 * * * sh /home/gccadmin/scripts/update_version_git
-50  0 * * * /home/gccadmin/venv/bin/python3 /home/gccadmin/scripts/update_web_docs_git.py /www/gcc/htdocs/onlinedocs/ --sphinx-build=/home/gccadmin/venv/bin/sphinx-build
+50  0 * * * sh /home/gccadmin/venv/bin/python3 /home/gccadmin/scripts/update_web_docs_git.py /www/gcc/htdocs/onlinedocs/ --sphinx-build=/home/gccadmin/venv/bin/sphinx-build
 55  0 * * * sh /home/gccadmin/scripts/update_web_docs_libstdcxx_git
 32 22 * * 4 sh /home/gccadmin/scripts/gcc_release -s 10:releases/gcc-10 -l -d /sourceware/snapshot-tmp/gcc all
 32 22 * * 5 sh /home/gccadmin/scripts/gcc_release -s 11:releases/gcc-11 -l -d /sourceware/snapshot-tmp/gcc all