Increase type_length_limit to 2121396

Previously rustc would fail with
error: reached the type-length limit while instantiating
`<std::vec::IntoIter<Peer> as std...rs:216:58: 220:6 keylog:&bool]]>`

(cherry picked from commit 817a57d281)

interop/src/main.rs

@@ -1,4 +1,5 @@
 #![allow(clippy::mutex_atomic, clippy::eval_order_dependence)]
+#![type_length_limit = "2121396"]
 
 use std::{
     env,

interop/src/qif.rs

@@ -1,3 +1,5 @@
+#![type_length_limit = "2121396"]
+
 /// Offline QPACK interop test tool
 ///
 /// QIF - Quic Interop File

interop/src/server.rs

@@ -1,3 +1,5 @@
+#![type_length_limit = "2121396"]
+
 use std::{
     ascii, cmp,
     ffi::OsStr,