test: move timing-dependent tests to sequential
Move test-http-server-keep-alive-timeout-slow-server
and test-http-server-keep-alive-timeout-slow-client-headers
from parallel to sequential to (hopefully) resolve test flakiness on freebsd10-64
.
Refs: https://github.com/nodejs/node/issues/14033 Refs: https://github.com/nodejs/node/pull/9317
/cc @nodejs/testing
Checklist
-
make -j4 test
(UNIX), orvcbuild test
(Windows) passes -
commit message follows commit guidelines
Affected core subsystem(s)
test