Don't run cancel_after_accept test for fd and socketpair fixtures.

test/core/end2end/end2end_tests.h

test/core/end2end/fixtures/h2_census.c

test/core/end2end/fixtures/h2_compress.c

test/core/end2end/fixtures/h2_fakesec.c

test/core/end2end/fixtures/h2_full+pipe.c

test/core/end2end/fixtures/h2_full+trace.c

test/core/end2end/fixtures/h2_full.c

test/core/end2end/fixtures/h2_http_proxy.c

test/core/end2end/fixtures/h2_load_reporting.c

test/core/end2end/fixtures/h2_oauth2.c

test/core/end2end/fixtures/h2_proxy.c

test/core/end2end/fixtures/h2_ssl.c

test/core/end2end/fixtures/h2_ssl_cert.c

test/core/end2end/fixtures/h2_ssl_proxy.c

test/core/end2end/fixtures/h2_uds.c

test/core/end2end/tests/cancel_after_accept.c