codecov: expect 5 flags to be submitted

Flags are:
- unittests
- suricata-verify
- pcap
- livemode
- fuzzcorpus

This should make sure codecov only adds its report after receiving
the results for each of the flags.

.github/codecov.yml

@@ -1,7 +1,7 @@
 codecov:
   require_ci_to_pass: false
   notify:
-    after_n_builds: 3
+    after_n_builds: 5
 
 coverage:
   precision: 2