zsh: Try splitting zprofile by OS

zsh/.zprofile

@@ -1,27 +0,0 @@
-source_if() {
-    if [ -e "$1" ]; then
-        source "$1"
-    fi
-}
-
-path_if() {
-    if [ -d "$1" ]; then
-        case ":$PATH:" in
-            *:"$1":*)
-                ;;
-            *)
-                PATH="${1}${PATH:+:$PATH}"
-        esac
-    fi
-}
-
-source_if "${HOME}/.nix-profile/etc/profile.d/nix.sh"
-
-path_if "$HOME/bin"
-path_if "$HOME/.local/bin"
-path_if /usr/local/bin
-path_if /opt/homebrew/bin
-path_if /opt/homebrew/sbin
-
-unset -f source_if
-unset -f path_if