Update src/rez/package_cache.py

Co-authored-by: Jean-Christophe Morin <38703886+JeanChristopheMorinPerso@users.noreply.github.com>
Signed-off-by: Ben Andersen <156872503+isohedronpipeline@users.noreply.github.com>

src/rez/package_cache.py

@@ -417,10 +417,7 @@ def add_variants_async(self, variants):
         return self.add_variants(variants, package_cache_async=True)
 
     def add_variants(self, variants, package_cache_async=True):
-        """Update the package cache by adding some or all of the given variants.
-
-        This method is called when a context is created or sourced. Variants
-        are then added to the cache in a separate process.
+        """Add the given variants to the package payload cache.
         """
 
         # A prod install is necessary because add_variants works by