in this ticket, we simplify bootstrap using the new options of sage -package list introduced in #30865.

The simplifications are similar to those done in #30947 for src/doc/bootstrap.

Depends on #30865

CC: @seblabbe

Component: build

Keywords: sd111

Author: Matthias Koeppe

Branch/Commit: f110916

Reviewer: Sébastien Labbé

Issue created by migration from https://trac.sagemath.org/ticket/30968