multiple spurious warnings for zsh path modifications

#### For bugs with existing features - Rule Id (if any, e.g. SC1000): SC2128 and SC2206 - My shellcheck version (`shellcheck --version` or "online"): 0.11.0 - [x] The rule's wiki page does not already cover this (e.g. https://shellcheck.net/wiki/SC2086) - [x] I tried on https://www.shellcheck.net/ and verified that this is still a problem on the latest commit #### Here's a snippet or screenshot that shows the problem: ```zsh typeset -Uga path path=( $path ~/src/github.com/BelaPlatform/Bela/scripts ) ``` #### Here's what shellcheck currently says: ```txt In src/.zshenv.d/bela.zsh line 3: $path ^---^ SC2128 (warning): Expanding an array without an index only gives the first element. ^---^ SC2206 (warning): Quote to prevent word splitting/globbing, or split robustly with mapfile or read -a. For more information: https://www.shellcheck.net/wiki/SC2128 -- Expanding an array without an ind... https://www.shellcheck.net/wiki/SC2206 -- Quote to prevent word splitting/g... ``` #### Here's what I wanted or expected to see: Nothing. The `path` variable in zsh is commonly `typeset -U[ga]`, often in external scripts from the one that ShellCheck is currently scanning (this script gets sourced). Enabling implicit, safe expansion in parentheses `(` ... `)`.