Fix one more destruction issue

Should now just be able to delete the internals PP on destruction

Author: b-pass

include/pybind11/detail/common.h

@@ -342,7 +342,11 @@
 #define PYBIND11_STRINGIFY(x) #x
 #define PYBIND11_TOSTRING(x) PYBIND11_STRINGIFY(x)
 #define PYBIND11_CONCAT(first, second) first##second
-#define PYBIND11_ENSURE_INTERNALS_READY pybind11::detail::get_internals();
+#define PYBIND11_ENSURE_INTERNALS_READY                                                           \
+    {                                                                                             \
+        pybind11::detail::get_internals_pp_manager().unref();                                     \
+        pybind11::detail::get_internals();                                                        \
+    }
 
 #if !defined(GRAALVM_PYTHON)
 #    define PYBIND11_PYCFUNCTION_GET_DOC(func) ((func)->m_ml->ml_doc)

include/pybind11/detail/internals.h

@@ -518,7 +518,7 @@ class internals_pp_manager {
 #if PYBIND11_HAS_SUBINTERPRETER_SUPPORT
         if (get_num_interpreters_seen() > 1) {
             auto *tstate = get_thread_state_unchecked();
-            // this could be called without an active interpreter, that's OK, just use what we
+            // this could be called without an active interpreter, just use what was cached
             if (!tstate || tstate->interp == last_istate_.get()) {
                 auto tpp = internals_tls_p_.get();
                 if (tpp) {
@@ -529,11 +529,7 @@ class internals_pp_manager {
             return;
         }
 #endif
-        // we can never delete the main interpreter PP because other modules may hold a copy of it
-        if (internals_singleton_pp_) {
-            // but we CAN and DO delete the internals inside.
-            internals_singleton_pp_->reset();
-        }
+        delete internals_singleton_pp_;
         unref();
     }