There's some more work before our consumers can switch to bullseye.
To make this process more tractable, revert the recent backport
addition, and specify that we want bullseye images from upstream.
That gets us back to where we were at the start of this. Next,
we can start building 2x images of python-base/builder and tag
them with bullseye or buster. Then the consumers can specify
which tags, then start switching.
Revert "Add backports repos to base and builder images"
This reverts commit b217e38904.
Revert "Update matrix-eavesdrop for bullseye"
This reverts commit fc38c69753.
Change-Id: Id21681342fe5268296128c1b09436a80c46e3169
45caec4d43