Yes, since EE doesn't use php5 anymore, you can safely comment out this here:
sudo nano /etc/cron.d/php5
you will see a similar line:
09,39 * * * * root [ -x /usr/lib/php5/sessionclean ] && /usr/lib/php5/sessionclean
change it to look like this:
# 09,39 * * * * root [ -x /usr/lib/php5/sessionclean ] && /usr/lib/php5/sessionclean
then exit and save the file.