message-capture-parser: fix AssertionError on parsing `headers` message

If a test framework message's field name is in the list of
`HASH_INT_VECTORS`, we currently assume that it _always_ has to contain
a vector of integers and throw otherwise (introduced in PR #25367,
commit 42bbbba7c8). However, that
assumption is too strict. In this concrete case, the (de)serialization
field name "headers" is used in two different message types, one for
`cfcheckpt` (where it is serialized as an integer vector), and another
time for `headers` (where it is serialized as a vector of
`CBlockHeader`s). Fix by adding the integer type check as additional
condition to the `HASH_INT_VECTORS` check rather than asserting.
Fixes #25954.

contrib/message-capture/message-capture-parser.py

@@ -79,8 +79,7 @@ def to_jsonable(obj: Any) -> Any:
             val = getattr(obj, slot, None)
             if slot in HASH_INTS and isinstance(val, int):
                 ret[slot] = ser_uint256(val).hex()
-            elif slot in HASH_INT_VECTORS:
-                assert all(isinstance(a, int) for a in val)
+            elif slot in HASH_INT_VECTORS and all(isinstance(a, int) for a in val):
                 ret[slot] = [ser_uint256(a).hex() for a in val]
             else:
                 ret[slot] = to_jsonable(val)