`buildscripts/download.sh`: a dead variable with broken syntax

2. buildscripts/download.sh: a dead variable with broken syntax

What happened: an early version of download.sh had this line, meant to optionally allow overriding the download tool:

[ -z "$WGET" ] && WGET=curl -L -o

This is invalid — in bash, = with a space after it stops being a plain variable assignment. WGET=curl gets set, and -L gets interpreted as a separate command to run, immediately failing CI with -L: command not found.

Root cause on inspection: the $WGET variable was never actually referenced anywhere else in the script — every fetch_* function called curl directly. It was dead, unused leftover.

Fix: deleted the line entirely.

Lesson: dead code that "looks like configuration" is worth deleting rather than leaving in — it added a bug with zero corresponding benefit.