diff --git a/pyproject.toml b/pyproject.toml
index 9035d3955..0830a91d4 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -73,7 +73,7 @@ packaging = [
   "check-manifest==0.50",
   "readme-renderer==44.0",
   "build>=1.2.2,<2",
-  "twine>=5.1.1,<6",
+  "twine>=6.1.0,<7",
   "wheel>=0.45.0,<1",
 ]
 
@@ -183,9 +183,6 @@ python = """
 """
 
 [tool.tox.env_run_base]
-pass_env = [
-  "GITHUB_*",
-]
 dependency_groups = ["testing"]
 commands = [
   ["python", "-bb", "-m", "pytest", "--cov-report=xml", "--cov-report=term", "--cov=h2", { replace = "posargs", extend = true }]
diff --git a/src/h2/stream.py b/src/h2/stream.py
index d102b056c..d6f5845c3 100644
--- a/src/h2/stream.py
+++ b/src/h2/stream.py
@@ -1037,7 +1037,7 @@ def receive_push_promise_in_band(self,
         events = self.state_machine.process_input(
             StreamInputs.RECV_PUSH_PROMISE,
         )
-        push_event = cast(PushedStreamReceived, events[0])
+        push_event = cast("PushedStreamReceived", events[0])
         push_event.pushed_stream_id = promised_stream_id
 
         hdr_validation_flags = self._build_hdr_validation_flags(events)
@@ -1076,7 +1076,7 @@ def receive_headers(self,
 
         events = self.state_machine.process_input(input_)
         headers_event = cast(
-            Union[RequestReceived, ResponseReceived, TrailersReceived, InformationalResponseReceived],
+            "Union[RequestReceived, ResponseReceived, TrailersReceived, InformationalResponseReceived]",
             events[0],
         )
 
@@ -1086,9 +1086,9 @@ def receive_headers(self,
             )
             # We ensured it's not an information response at the beginning of the method.
             cast(
-                Union[RequestReceived, ResponseReceived, TrailersReceived],
+                "Union[RequestReceived, ResponseReceived, TrailersReceived]",
                 headers_event,
-            ).stream_ended = cast(StreamEnded, es_events[0])
+            ).stream_ended = cast("StreamEnded", es_events[0])
             events += es_events
 
         self._initialize_content_length(headers)
@@ -1112,7 +1112,7 @@ def receive_data(self, data: bytes, end_stream: bool, flow_control_len: int) ->
             "set to %d", self, end_stream, flow_control_len,
         )
         events = self.state_machine.process_input(StreamInputs.RECV_DATA)
-        data_event = cast(DataReceived, events[0])
+        data_event = cast("DataReceived", events[0])
         self._inbound_window_manager.window_consumed(flow_control_len)
         self._track_content_length(len(data), end_stream)
 
@@ -1120,7 +1120,7 @@ def receive_data(self, data: bytes, end_stream: bool, flow_control_len: int) ->
             es_events = self.state_machine.process_input(
                 StreamInputs.RECV_END_STREAM,
             )
-            data_event.stream_ended = cast(StreamEnded, es_events[0])
+            data_event.stream_ended = cast("StreamEnded", es_events[0])
             events.extend(es_events)
 
         data_event.data = data
@@ -1144,7 +1144,7 @@ def receive_window_update(self, increment: int) -> tuple[list[Frame], list[Event
         # this should be treated as a *stream* error, not a *connection* error.
         # That means we need to catch the error and forcibly close the stream.
         if events:
-            cast(WindowUpdated, events[0]).delta = increment
+            cast("WindowUpdated", events[0]).delta = increment
             try:
                 self.outbound_flow_control_window = guard_increment_window(
                     self.outbound_flow_control_window,
@@ -1228,7 +1228,7 @@ def stream_reset(self, frame: RstStreamFrame) -> tuple[list[Frame], list[Event]]
 
         if events:
             # We don't fire an event if this stream is already closed.
-            cast(StreamReset, events[0]).error_code = _error_code_from_int(frame.error_code)
+            cast("StreamReset", events[0]).error_code = _error_code_from_int(frame.error_code)
 
         return [], events