fix build fails

MANIFEST.in

@@ -18,8 +18,10 @@ recursive-include docs *
 recursive-include scripts *
 recursive-include scripts-dev *
 recursive-include synapse *.pyi
-recursive-include tests *.pem
 recursive-include tests *.py
+include tests/http/ca.crt
+include tests/http/ca.key
+include tests/http/server.key
 
 recursive-include synapse/res *
 recursive-include synapse/static *.css

changelog.d/5417.bugfix

@@ -0,0 +1 @@
+Fix excessive memory using with default `federation_verify_certificates: true` configuration.