[3.15] gh-151842: Fix crash upon OOM in _interpreters.capture_exception (GH-151843) (GH-152031)

(cherry picked from commit 5e0747db2f)

Co-authored-by: Amrutha <amruthamodela06@gmail.com>

Python/crossinterp.c

@@ -1689,6 +1689,7 @@ _PyXI_NewExcInfo(PyObject *exc)
     }
     _PyXI_excinfo *info = PyMem_RawCalloc(1, sizeof(_PyXI_excinfo));
     if (info == NULL) {
+        PyErr_NoMemory();
         return NULL;
     }
     const char *failure;
@@ -1709,6 +1710,7 @@ _PyXI_NewExcInfo(PyObject *exc)
 void
 _PyXI_FreeExcInfo(_PyXI_excinfo *info)
 {
+    assert(info != NULL);
     _PyXI_excinfo_clear(info);
     PyMem_RawFree(info);
 }