fix(changelog): fix for `${(@ps:$sep:)var}` construct in zsh < 5.0.8
fix(changelog): fix for `${(@ps:$sep:)var}` construct in zsh < 5.0.8

In recent zsh versions, `${(@ps:$sep:)var}` where $sep is a variable containing
a separator string and $var is a string with multiple values separated by $sep,
the `p` flag makes zsh correctly expand $sep before splitting $var. In versions
older than 5.0.8, this doesn't happen, so we use `eval` to get the same effect.

tekniklr/oh-my-zsh,tekniklr/oh-my-zsh