wip: Work around Hummingbird thread safety issue 574

Author: euanh

Examples/HelloWorldHummingbird/Package.resolved

@@ -1,5 +1,5 @@
 {
-  "originHash" : "1f7541443d71102242262e529437bff9041ff786639686ffd1c881fab4618aa7",
+  "originHash" : "decba78b8f67eff9f64d306213f189b80e3ce82d89a5b4ee9e98c4996375779e",
   "pins" : [
     {
       "identity" : "async-http-client",
@@ -15,8 +15,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/hummingbird-project/hummingbird.git",
       "state" : {
-        "revision" : "d4f792d209f02b26a17c0105751220da65207fb2",
-        "version" : "2.0.1"
+        "branch" : "pull/573/head",
+        "revision" : "60fffd6060212d888cb6e307cb27cf58aefd1415"
       }
     },
     {

Examples/HelloWorldHummingbird/Package.swift

@@ -20,7 +20,7 @@ let package = Package(
     name: "hello-world",
     platforms: [.macOS(.v14)],
     dependencies: [
-        .package(url: "https://github.com/hummingbird-project/hummingbird.git", from: "2.0.0"),
+        .package(url: "https://github.com/hummingbird-project/hummingbird.git", branch: "pull/573/head"),
         .package(url: "https://github.com/apple/swift-container-plugin", from: "0.1.0"),
     ],
     targets: [