Ensure all weak static lookups are thread-safe

Author: pimterry

src/main/java/tech/httptoolkit/javaagent/advice/akka/ResetOldGatewaysAdvice.java

@@ -18,7 +18,9 @@
 // one per config, rather than one PoolMaster instance. Otherwise the logic should be identical.
 public class ResetOldGatewaysAdvice {
 
-    public static Set<HostConnectionPoolSetup> resetPoolSetups = Collections.newSetFromMap(new WeakHashMap<>());
+    public static Set<HostConnectionPoolSetup> resetPoolSetups = Collections.newSetFromMap(
+        Collections.synchronizedMap(new WeakHashMap<>())
+    );
 
     @Advice.OnMethodEnter
     public static void beforeDispatchRequest(

src/main/java/tech/httptoolkit/javaagent/advice/akka/ResetOldPoolsAdvice.java

@@ -16,7 +16,9 @@
 
 public class ResetOldPoolsAdvice {
 
-    public static Set<PoolId> resetPoolIds = Collections.newSetFromMap(new WeakHashMap<>());
+    public static Set<PoolId> resetPoolIds = Collections.newSetFromMap(
+            Collections.synchronizedMap(new WeakHashMap<>())
+    );
 
     @Advice.OnMethodEnter
     public static void beforeDispatchRequest(

src/main/java/tech/httptoolkit/javaagent/advice/asynchttpclient/AsyncHttpResetSslEngineFactoryAdvice.java

@@ -12,7 +12,9 @@ public class AsyncHttpResetSslEngineFactoryAdvice {
 
     // Track each ChannelManager with a weak ref, to avoid unnecessary reflection overhead by only
     // initializing them once, instead of every request
-    public static Set<Object> patchedChannelManagers = Collections.newSetFromMap(new WeakHashMap());
+    public static Set<Object> patchedChannelManagers = Collections.newSetFromMap(
+        Collections.synchronizedMap(new WeakHashMap<>())
+    );
 
     @Advice.OnMethodEnter
     public static void createSslHandler(

src/main/java/tech/httptoolkit/javaagent/advice/jettyclient/JettyResetDestinationsAdvice.java

@@ -12,7 +12,9 @@ public class JettyResetDestinationsAdvice {
 
     // Track each client with a weak ref, to avoid unnecessary reflection overhead by only
     // initializing them once, instead of every request
-    public static Set<Object> patchedHttpClients = Collections.newSetFromMap(new WeakHashMap());
+    public static Set<Object> patchedHttpClients = Collections.newSetFromMap(
+            Collections.synchronizedMap(new WeakHashMap<>())
+    );
 
     @Advice.OnMethodEnter
     public static void beforeResolveDestination(