Use standard base repo in SLES 12 (#55135)

The SLES 12 image's repos appear to no longer have any standard repos.
This commit adds the the standard SLES 12 SP3 repo, and forces expect to
be resolved as it has an issue with the version of tcl/tck (those
packages are thus downgraded to get expect installed).

closes #55048

Vagrantfile

@@ -329,8 +329,12 @@ end
 
 def sles_common(config, name)
   extra = <<-SHELL
-    zypper rr systemsmanagement_puppet puppetlabs-pc1
+    zypper rr systemsmanagement_puppet puppetlabs-pc1 devel_tools_scm
+    zypper ar http://download.opensuse.org/distribution/12.3/repo/oss/ oss
+    zypper --non-interactive  --gpg-auto-import-keys refresh
     zypper --non-interactive install git-core
+    # choose to "ignore some dependencies" of expect, which has a problem with tcl... 
+    zypper --non-interactive install --force-resolution expect
   SHELL
   suse_common config, name, extra: extra
 end