MonitorPtrace: Remove no longer needed stacktrace recursion check

Also remove the no longer needed friend declaration.

PiperOrigin-RevId: 734115426
Change-Id: I631f8c7d8bb76c5f7e8aecec814f4b82af6daf82

Author: happyCoder92

sandboxed_api/sandbox2/executor.h

@@ -39,7 +39,6 @@ namespace sandbox2 {
 
 // Forward declarations for friend declarations.
 class MonitorBase;
-class PtraceMonitor;
 class StackTracePeer;
 
 // The sandbox2::Executor class is responsible for both creating and executing
@@ -107,7 +106,6 @@ class Executor final {
 
  private:
   friend class MonitorBase;
-  friend class PtraceMonitor;
   friend class StackTracePeer;
 
   // Internal constructor for executing libunwind on the given pid

sandboxed_api/sandbox2/monitor_ptrace.cc

@@ -912,7 +912,6 @@ void PtraceMonitor::StateProcessStopped(pid_t pid, int status) {
   }
 
   if (ABSL_PREDICT_FALSE(pid == process_.main_pid && should_dump_stack_ &&
-                         executor_->libunwind_sbox_for_pid_ == 0 &&
                          policy_->GetNamespace())) {
     auto stack_trace = [this,
                         pid]() -> absl::StatusOr<std::vector<std::string>> {