tests: Make sudo-longopt pass when sudo isn't installed.
tests: Make sudo-longopt pass when sudo isn't installed.

Fixes #673.

phy1729/zsh-syntax-highlighting,P71/zsh-syntax-highlighting,zsh-users/zsh-syntax-highlighting,zsh-users/zsh-syntax-highlighting,x-way/zsh-syntax-highlighting,x-way/zsh-syntax-highlighting,P71/zsh-syntax-highlighting,phy1729/zsh-syntax-highlighting