Account for duplicate srpms in count when skipping srpms

The issue involved counting duplicate srpms when creating the package
count for primary.xml which led the check against filelists.xml to fail.
To create a unique package count, we're storing srpms we've seen thereby
not counting them if we've seen the NEVRA already.

fixes #4397
https://pulp.plan.io/issues/4397

plugins/pulp_rpm/plugins/importers/yum/sync.py

@@ -1059,6 +1059,7 @@ def _identify_wanted_versions(self, package_info_generator):
         # values are dicts where keys are serialized versions, and values are
         # a tuple of (model as named tuple, size in bytes)
         wanted = {}
+        srpms = []  # keep track of srpms to avoid counting dupes
 
         skip_srpm = ids.TYPE_ID_SRPM in self.config.get(constants.CONFIG_SKIP, [])
         number_old_versions_to_keep = \
@@ -1070,7 +1071,10 @@ def _identify_wanted_versions(self, package_info_generator):
 
         for model in package_info_generator:
             if skip_srpm and isinstance(model, models.SRPM):
-                number_of_unique_packages += 1
+                unit_key = models.NEVRA._fromdict(model.unit_key)
+                if unit_key not in srpms:
+                    srpms.append(unit_key)
+                    number_of_unique_packages += 1
                 continue
 
             versions = wanted.setdefault(model.key_string_without_version, {})