Clarify docs too: events can be any sequence (not that the C code supports it)

Doc/library/xml.etree.elementtree.rst

@@ -411,7 +411,7 @@ Functions
 
    Parses an XML section into an element tree incrementally, and reports what's
    going on to the user.  *source* is a filename or :term:`file object`
-   containing XML data.  *events* is a list of events to report back.  The
+   containing XML data.  *events* is a sequence of events to report back.  The
    supported events are the strings ``"start"``, ``"end"``, ``"start-ns"``
    and ``"end-ns"`` (the "ns" events are used to get detailed namespace
    information).  If *events* is omitted, only ``"end"`` events are reported.
@@ -875,8 +875,8 @@ IncrementalParser Objects
 .. class:: IncrementalParser(events=None, parser=None)
 
    An incremental, event-driven parser suitable for non-blocking applications.
-   *events* is a list of events to report back.  The supported events are the
-   strings ``"start"``, ``"end"``, ``"start-ns"`` and ``"end-ns"`` (the "ns"
+   *events* is a sequence of events to report back.  The supported events are
+   the strings ``"start"``, ``"end"``, ``"start-ns"`` and ``"end-ns"`` (the "ns"
    events are used to get detailed namespace information).  If *events* is
    omitted, only ``"end"`` events are reported.  *parser* is an optional
    parser instance.  If not given, the standard :class:`XMLParser` parser is