Closes #28645. Bugfix v0.2.0.

To test that torflow's scaling is using the minimum of all the
descriptor bandwidth values.

from sbws scaling to torflow's scaling, where the descriptor
bandwidth is calculated from the minimum of all the descriptor
bandwidth values.
And use the bandwidth-file-spec.txt text instead.

v3bwfile: replace desc_bw_obs by desc_bw

Torflow's scaling takes the minimum of all the descriptor
bandwidth values, not only the descriptor observed bandwidth.

And method to obtain it from results.

This way it can be obtained in a different way (for instance, the
mean, not the last) and it also avoids not obtaining any value in
case the last is None.

In order to use it in torflow's scaling method.

In order to use it in torflow's scaling method

Instead create a changelog before new releases.

Closes ticket #28572.

sbws should exclude results, then check for the minimum number of results.

Closes bug 28572.

Even if that method is call from generate with torflow's scaling
by default.

So that is less confusing that it's the default.
We already have an option for linear scaling and no scaling.

Continue running with defaults when the config argument is provided
but not found. This could be the case of system packages.

sbws is getting a significant number of build failures due to keyserver failures.

Using the high-availability keyserver pool reduces the probability of failure.

Implements part of proposal 276.

Implements 28451.

Part of 28442.

And add unit tests for rounding and rounding error.

Bugfix on 27337 in sbws 1.0.

Part of 28442.

Include the headers about eligible relays in all the bandwidth
files, not only in the ones that does not have enough eligible
relays (#28365).