Update gating (tier0) configuration

- Update outdated FMF/TMT constructs
- Simplify tier0 testing, component rebuilds are an overkill
  in tier0

ci.fmf

@@ -1,19 +1,11 @@
-/test:
-    summary:
-        CI plan
-    description:
-        CI plan
+summary: tier0 test plan
 discover:
-      - name: ltrace_smoke
   how: fmf
-        test: ["/Sanity/testsuite"]
-        url: "https://src.fedoraproject.org/rpms/ltrace.git"
-      - name: memstomp_smoke
-        how: fmf
-        test: ["/Sanity/memstomp-testsuite"]
-        url: "https://src.fedoraproject.org/rpms/memstomp.git"
-      - name: local_tests
-        how: fmf
-        directory: tests
 execute:
   how: tmt
+prepare+:
+  - how: shell
+    script:
+      - dnf config-manager --set-enabled '*CRB' || true
+      - dnf config-manager --set-enabled '*crb' || true
+      - dnf config-manager --set-enabled '*codeready*' || true

tests/show_version/main.fmf

@@ -0,0 +1,4 @@
+summary: the binary runs and know the --version option
+require: dejagnu
+test: dejagnu --version
+duration: 5m