Add simple interoperability test with Cloudflare quiche

This is an external test which requires recursive checkout
of the cloudflare-quiche submodule.

We simply run a client against the example quiche-server
serving HTTP/0.9 requests.

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/20527)

1 files changed, 0 insertions, 0 deletions

diff --git a/cloudflare-quiche b/cloudflare-quiche
new file mode 160000
+Subproject 24a959abf115923910ce18985aa199d85fb602d