libdebuginfod: set default urls

[sgn]

General

• This is a new package and it conforms to the quality requirements

Have the results of the proposed changes been tested?

• I use the packages affected by the proposed changes on a regular basis and confirm this PR works for me
• I generally don't use the affected packages but briefly tested this PR

[Chocimier]

Phoning home by default isn't in spirit of Void.
I would prefer this to be put into documentation.

[ericonr]

We could move the etc/profile.d files to a subpackage? This way it's opt-in, but easier than setting the env var manually.

[sgn]

it's set once and forget, I'm not sure if a package with unmodified contents updating whenever libdebuginfod updated make sense.
Closing this but feel free to continue discussion.