fix: executionContextCleared test flake

1. Execution contexts are cleared and we start waiting on shutdown
2. New scripts come in
3. Shutdown resolves and we incorrectly discard new scripts and context

src/adapter/threads.ts

@@ -884,11 +884,18 @@ export class Thread implements IVariableStoreLocationProvider {
   }
 
   async _executionContextsCleared() {
+    const removedContexts = [...this._executionContexts.values()];
+    const pausedDetails = this._pausedDetails;
     this._executionContexts.clear();
     await this.shutdown.shutdownContext();
-    this._removeAllScripts();
+    for (const context of removedContexts) {
+      context.remove(this._sourceContainer);
+    }
     this._breakpointManager.executionContextWasCleared();
-    if (this._pausedDetails) this.onResumed();
+
+    if (pausedDetails && pausedDetails === this._pausedDetails) {
+      this.onResumed();
+    }
   }
 
   _ensureDebuggerEnabledAndRefreshDebuggerId() {