Fix macOS PATH being rewritten in /etc/zprofile

macOS is obnoxious and overwrites the PATH from a users ~/.zshenv, which is
sourced first, in /etc/zprofile by calling `/usr/libexec/path_helper -s` so
this is required so that PATH is once again set to the desired value.

zshrc

@@ -158,22 +158,6 @@ fi
 # Load work related config
 [ -f ~/.config/work/zshrc ] && source ~/.config/work/zshrc
 
-# Remove duplicates from environment variables
-typeset -U PATH
-typeset -U MANPATH
-typeset -U INFOPATH
-
-# Add ccache symlink directory to start of PATH, this must be after
-# `typeset -U PATH` because on macOS this reorders the list so ccache's
-# symlinks will no longer be at the start of PATH rendering it unusable.
-if [ `uname` = Darwin ]; then
-  [ -f /usr/local/bin/ccache ] && \
-    PATH=/usr/local/opt/ccache/libexec:$PATH
-else
-  [ -f /usr/bin/ccache ] && \
-    PATH=/usr/lib/ccache:$PATH
-fi
-
 # Aliases
 alias grep='grep --color=always'
 which cmake &> /dev/null && \