Revert "Try to unflake JSON API failure tests (#9855)" (#9887)

This has made things worse not better. Now tests that should be
successful hit the timeout.

Still not sure what is actually going wrong so marking it as flaky
Tracked in #9886

changelog_begin
changelog_end

ledger-service/http-json/BUILD.bazel

@@ -364,6 +364,8 @@ alias(
             "//ledger/test-common/test-certificates",
             "@toxiproxy_dev_env//:bin/toxiproxy-cmd" if not is_windows else "@toxiproxy_dev_env//:toxiproxy-server-windows-amd64.exe",
         ],
+        # See https://github.com/digital-asset/daml/issues/9886
+        flaky = True,
         plugins = [
             "@maven//:org_typelevel_kind_projector_{}".format(scala_version_suffix),
         ],

ledger-service/http-json/src/failure/resources/application.conf

@@ -1,6 +0,0 @@
-akka {
-  # Reducing this should hopefully ensure that the tests
-  # that test for timeouts always hit the server side request timeout
-  # and not another timeout somewhere in akka-http.
-  http.server.request-timeout = 5 s
-}