Add a fedora-archive repo

Certain kola tests on older RHCOS branches rely on EOL fedora
containers to set up and run the test environment. Right now,
the older content can be found on the mirrors, but as part of the
RHCOS pipeline migration effort to the ITUP cluster, we have to
explicitly specify each outbound connection.

Add a `fedora-archive.repo` file to be used in these tests so we can
always download the older content from: https://dl.fedoraproject.org

see: coreos#3123 (comment)

fedora-archive.repo

@@ -0,0 +1,12 @@
+[fedora-archive]
+name=Fedora $releasever - $basearch
+baseurl=https://dl.fedoraproject.org/pub/archive/fedora/linux/releases/$releasever/Everything/$basearch/os/
+        https://dl.fedoraproject.org/pub/archive/fedora-secondary/releases/$releasever/Everything/$basearch/os/
+#metalink=https://mirrors.fedoraproject.org/metalink?repo=fedora-$releasever&arch=$basearch
+enabled=1
+#metadata_expire=7d
+repo_gpgcheck=0
+type=rpm
+gpgcheck=1
+gpgkey=file:///usr/share/distribution-gpg-keys/fedora/RPM-GPG-KEY-fedora-$releasever-primary
+skip_if_unavailable=False