ref(deps): Upgrade to iroh 0.4.0 (#4245)

This moves us back to a released version;

- Ticket is now opaque, need to use accessor functions.

- Ticket now ensures it is valid itself, no need to inspect it's
  inners.  Deserialisation would fail if it was bad.

- The git version was accidentally used with default-features enabled
  and thus pulled in a few too many dependencies.  They are now gone.

deny.toml

@@ -28,7 +28,6 @@ skip = [
      { name = "humantime", version = "<2.1" },
      { name = "idna", version = "<0.3" },
      { name = "nom", version = "<7.1" },
-     { name = "portable-atomic", version = "<1.0" },
      { name = "quick-error", version = "<2.0" },
      { name = "rand", version = "<0.8" },
      { name = "rand_chacha", version = "<0.3" },
@@ -75,6 +74,5 @@ license-files = [
 github = [
        "async-email",
        "deltachat",
-       "n0-computer",
        "quinn-rs",
 ]