get rid of remote old style packages

[videlec]

Many efforts have been done to convert old style packages to new style ones. This ticket proposes to get rid of the possibility of installing remote old style packages, i.e. forbid sage -i package_name (but not sage -i /path/to/downloaded/tarball.spkg).

The (somehow outdated, see #19220) list of old style packages is available at:

• http://files.sagemath.org/spkg/optional/list
• http://files.sagemath.org/spkg/experimental/list

Depends on #19213

CC: @nexttime @jdemeyer @jhpalmieri @vbraun @tscrim

Component: scripts

Reviewer: Travis Scrimshaw

Issue created by migration from https://trac.sagemath.org/ticket/21132

[videlec]

Dependencies: #19213

[embray]

comment:3

Could we remove support for them completely, at this point (remote as well as local)?

[mkoeppe]

comment:5

Replying to @embray:

Could we remove support for them completely, at this point (remote as well as local)?

Done in #29289

[mkoeppe]

Reviewer: Travis Scrimshaw