Fix: Pipeline dependency on deb.debian.org, replace with archive

[reglim]

This should fix some tests, as a lot of them are dependent on deb.debian.org which no longer supports Debian 9 "Stretch". Instead we use archive.debian.org which will continue to contain "Stretch" packages for a long time.

Requirements

All new code should be covered with tests, documentation should be updated. CI should pass.

Description of the Change

Replace deb.debian.org/debian with archive.debian.org/debian-archive.

Why this change is important?

The tests should work

Checklist

• [ ] unit-test added (if change is algorithm)
• [ ] functional test added/updated (if change is functional)
• [ ] man page updated (if applicable)
• [ ] bash completion updated (if applicable)
• [ ] documentation updated
• [x] author name in AUTHORS

[codecov[bot]]

Codecov Report

Merging #1180 (30d777d) into master (9c6f896) will not change coverage. The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #1180   +/-   ##
=======================================
  Coverage   65.99%   65.99%           
=======================================
  Files         143      143           
  Lines       16196    16196           
=======================================
  Hits        10688    10688           
  Misses       4754     4754           
  Partials      754      754           

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