[gardening] Remove standalone/io/http_redirect_test from iso-stress builder
[gardening] Remove standalone/io/http_redirect_test from iso-stress builder

This test was modified (in [0]) to use `dart:mirrors` which doesn't
work in AOT mode. Only tests that work in AOT are considered for
the iso-stress builder.

[0] https://dart-review.googlesource.com/c/sdk/+/230600

TEST=Fixes "iso-stress" builder failure to compile.

Change-Id: I354784a33550d816332611747c4d41b53d44b2a4
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/232621
Reviewed-by: Daco Harkes <930cbae0ca77f1954c53e32620d89cfcca318f00@google.com>
Commit-Queue: Martin Kustermann <a35dd5b79fac84b2bb3b026a16b8becc55af5961@google.com>

dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk