Rephrase !PyErr_Occurred() comment: may=>can

Issue #29259.

Objects/abstract.c

@@ -2233,7 +2233,7 @@ PyObject_Call(PyObject *callable, PyObject *args, PyObject *kwargs)
     PyObject *result;
 
     /* PyObject_Call() must not be called with an exception set,
-       because it may clear it (directly or indirectly) and so the
+       because it can clear it (directly or indirectly) and so the
        caller loses its exception */
     assert(!PyErr_Occurred());
     assert(PyTuple_Check(args));
@@ -2309,7 +2309,7 @@ _PyObject_FastCallDict(PyObject *callable, PyObject **args, Py_ssize_t nargs,
     PyObject *result = NULL;
 
     /* _PyObject_FastCallDict() must not be called with an exception set,
-       because it may clear it (directly or indirectly) and so the
+       because it can clear it (directly or indirectly) and so the
        caller loses its exception */
     assert(!PyErr_Occurred());
 

Objects/methodobject.c

@@ -95,7 +95,7 @@ _PyMethodDef_RawFastCallDict(PyMethodDef *method, PyObject *self, PyObject **arg
     int flags;
 
     /* _PyMethodDef_RawFastCallDict() must not be called with an exception set,
-       because it may clear it (directly or indirectly) and so the
+       because it can clear it (directly or indirectly) and so the
        caller loses its exception */
     assert(!PyErr_Occurred());
 

Objects/object.c

@@ -477,7 +477,7 @@ PyObject_Repr(PyObject *v)
 
 #ifdef Py_DEBUG
     /* PyObject_Repr() must not be called with an exception set,
-       because it may clear it (directly or indirectly) and so the
+       because it can clear it (directly or indirectly) and so the
        caller loses its exception */
     assert(!PyErr_Occurred());
 #endif
@@ -526,7 +526,7 @@ PyObject_Str(PyObject *v)
 
 #ifdef Py_DEBUG
     /* PyObject_Str() must not be called with an exception set,
-       because it may clear it (directly or indirectly) and so the
+       because it can clear it (directly or indirectly) and so the
        caller loses its exception */
     assert(!PyErr_Occurred());
 #endif

Objects/typeobject.c

@@ -887,7 +887,7 @@ type_call(PyTypeObject *type, PyObject *args, PyObject *kwds)
 
 #ifdef Py_DEBUG
     /* type_call() must not be called with an exception set,
-       because it may clear it (directly or indirectly) and so the
+       because it can clear it (directly or indirectly) and so the
        caller loses its exception */
     assert(!PyErr_Occurred());
 #endif

Python/ceval.c

@@ -1046,7 +1046,7 @@ _PyEval_EvalFrameDefault(PyFrameObject *f, int throwflag)
 
 #ifdef Py_DEBUG
     /* PyEval_EvalFrameEx() must not be called with an exception set,
-       because it may clear it (directly or indirectly) and so the
+       because it can clear it (directly or indirectly) and so the
        caller loses its exception */
     assert(!PyErr_Occurred());
 #endif