Remove 'obsoletes'

This is unnecessary, according to Igor.

re: #5071
https://pulp.plan.io/issues/5071

plugins/pulp_rpm/plugins/importers/yum/pulp_solv.py

@@ -365,7 +365,7 @@ def module_solvable_name(unit):
 
     def module_basic_deps(pool, solvable, solvable_name, name, stream, version, arch):
         """
-        Create the basic module `Provides:` and `Obsoletes:` relations
+        Create the basic module `Provides:` relations
         """
         # Prv: module:$n:$s:$v:$c . $a
         solvable.nsvca_rel = pool.rel2id(
@@ -382,11 +382,6 @@ def module_basic_deps(pool, solvable, solvable_name, name, stream, version, arch
         dep_n = pool.Dep('module({})'.format(name))
         solvable.add_deparray(solv.SOLVABLE_PROVIDES, dep_n)
 
-        # Obs: module($n)
-        # This is a bit of a hack; a weaker than `Conflicts` because same-name module streams should
-        # repulse each other.
-        solvable.add_deparray(solv.SOLVABLE_OBSOLETES, dep_n)
-
         # Prv: module($n:$s)
         dep_ns = pool.Dep('module({}:{})'.format(name, stream))
         solvable.add_deparray(solv.SOLVABLE_PROVIDES, dep_ns)