Reduce the things we ignore in test/

Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4507)

.gitignore

@@ -60,12 +60,7 @@ Makefile
 /test/ossl_shim/ossl_shim
 
 # Certain files that get created by tests on the fly
-/test/*.ss
-/test/*.srl
-/test/.rnd
-/test/test*.pem
-/test/newkey.pem
-/test/*.log
+/test/test-runs
 /test/buildtest_*
 
 # Fuzz stuff.