[Feat]: please do not download sqlite (or anything else) during build

Problem

https://github.com/netdata/netdata/pull/21779 introduced a mandatory fetch of external sources during build time, which is a sandbox violation in build systems concerned with integrity and consistency.

Description

Please, if you absolutely must rely on external sources, at least also provide a build option that allows those sources to be provided from verified local files. As written, packaging/cmake/Modules/NetdataSQLite.cmake admits no way to prevent it from calling the Internet when building Netdata.

This behavior can be patched away in some sandboxed build systems, e.g. Gentoo Portage, to force CMake into using verified local sources but no such patch is upstreamable, introducing additional unnecessary downstream maintenance burdens.

Importance

really want

Value proposition

Sandboxed builds are good. Build integrity and consistency demand that no resource required to complete a build be held on or fetched from potentially unreliable media.

Proposed implementation

No response