make a bunch of changes so complement works again

Well, kinda. It crashed on me after 10 minutes because the tests timed
out like in <https://github.com/matrix-org/complement/issues/394>.
Sounds like this means it's a them problem though.

I want to use Nix to build this image instead in the future but this
will at least make it work for now and give me a reference for while I'm
porting it. I also want to make Conduit natively understand Complement's
requirements instead of `sed`ing a bunch of stuff and needing a reverse
proxy in the container. Should be more reliable that way.

I'm not making this run in CI until the above stuff is addressed and
until I can decide on a way to pin the revision of Complement being
tested against.

flake.nix

@@ -234,6 +234,13 @@
           toolchain
         ] ++ (with pkgsHost; [
           engage
+
+          # Needed for Complement
+          go
+          olm
+
+          # Needed for our script for Complement
+          jq
         ]);
       };
     });