fix(gentoo): fix the color of the prompt symbol (#9885)

This commit fixes an issue where the prompt symbol is white when vcs_info is displayed in the gentoo theme.

themes/gentoo.zsh-theme

@@ -25,4 +25,4 @@ gentoo_precmd() {
 autoload -U add-zsh-hook
 add-zsh-hook precmd gentoo_precmd
 
-PROMPT='%(!.%B%F{red}.%B%F{green}%n@)%m %F{blue}%(!.%1~.%~) ${vcs_info_msg_0_}%(!.#.$)%k%b%f '
+PROMPT='%(!.%B%F{red}.%B%F{green}%n@)%m %F{blue}%(!.%1~.%~) ${vcs_info_msg_0_}%F{blue}%(!.#.$)%k%b%f '