Update the executor image from Container Linux to Fedora CoreOS

[kleesc]

Description of Changes

• Update the build executor's image from Container Linux to Fedora CoreOS
• https://quay.io/repository/quay/quay-builder-qemu-fedoracoreos

Issue: PROJQUAY-704

TESTING ->

BREAKING CHANGE ->

---

Reviewer Checklist

• It works!
• Comments provide sufficient explanations for the next contributor
• Tests cover changes and corner cases
• Follows Quay syntax patterns and format

[kleesc]

@josephschorr Ping
Tested on both aws and qemu. Both were able to boot, but failed to connect back to Quay (as expected since it's being run locallty)

Jul 13 21:24:13 c3d2032b-6519-4f56-a35a-5c5a875ec540 docker[1835]: time="2020-07-13T21:24:13Z" level=info msg="55670558-ead8-4551-9a85-87bec83bc76e: attempting to connect to websocket wss://quay:8443/b1/socket"
Jul 13 21:24:13 c3d2032b-6519-4f56-a35a-5c5a875ec540 docker[1835]: time="2020-07-13T21:24:13Z" level=warning msg="55670558-ead8-4551-9a85-87bec83bc76e: Got error when connecting to build manager: dial tcp: look>
Jul 13 21:24:13 c3d2032b-6519-4f56-a35a-5c5a875ec540 docker[1835]: time="2020-07-13T21:24:13Z" level=info msg="55670558-ead8-4551-9a85-87bec83bc76e: Sleeping for 16 seconds (attempt #4 of 5)"
Jul 13 21:24:29 c3d2032b-6519-4f56-a35a-5c5a875ec540 docker[1835]: time="2020-07-13T21:24:29Z" level=info msg="55670558-ead8-4551-9a85-87bec83bc76e: attempting to connect to websocket wss://quay:8443/b1/socket"
Jul 13 21:24:29 c3d2032b-6519-4f56-a35a-5c5a875ec540 docker[1835]: time="2020-07-13T21:24:29Z" level=fatal msg="55670558-ead8-4551-9a85-87bec83bc76e: dial tcp: lookup quay on 10.0.2.3:53: no such host"
Jul 13 21:24:29 c3d2032b-6519-4f56-a35a-5c5a875ec540 systemd[1]: quay-builder.service: Main process exited, code=exited, status=1/FAILURE

[josephschorr]

LGTM

[dustymabe]

🎉 Does this mean quay builders run on FCOS now?

[josephschorr]

@dustymabe Once its tested and deployed and not on prem (yet)