fix: disable HTTP/2 to eliminate CONNECT-tunnel churn under concurrency

When the same twikit Client is shared across high-concurrency tasks (or
when many clients share an upstream CONNECT proxy), ``http2=True``
produces two failure modes that surface as ``ConnectError`` /
``[SSL: RECORD_LAYER_FAILURE]`` and 502s in the calling service:

1. httpx opens a new CONNECT tunnel per concurrent task at race time,
   then closes it once another task wins the multiplexing race on an
   already-open h2 connection. In production, 3proxy logs ~67% of
   tunnels with error code 21 (client closed before sending TLS data),
   leaving only ~26% of tunnels actually carrying traffic.

2. ALPN-negotiated h2 through CONNECT exposes a Cloudflare bot-detection
   RST path mid-handshake that surfaces as ``RECORD_LAYER_FAILURE`` for
   ~10% of requests originating from datacenter IPs. HTTP/1.1 with
   keep-alive avoids the negotiation entirely and Cloudflare lets it
   through.

X.com's GraphQL is HTTP/1.1-friendly, and the perf cost of dropping h2
is negligible at this concurrency profile (the keep-alive pool was the
bottleneck, not stream multiplexing). Apply the same change to the guest
client so unauthenticated calls share the same transport behaviour.

Author: kasparasizi1

twikit/client/client.py

@@ -111,8 +111,18 @@ def __init__(
             )
             warnings.warn(message)
 
-        # Initialize with an isolated cookie jar to prevent cookie conflicts
-        self.http = AsyncClient(proxy=proxy, cookies=Cookies(), http2=True, **kwargs)
+        # Initialize with an isolated cookie jar to prevent cookie conflicts.
+        #
+        # ``http2=False`` is intentional: when scraping at high concurrency
+        # through a CONNECT proxy, httpx with HTTP/2 opens speculative
+        # tunnels per concurrent task, then closes them un-used as
+        # multiplexed streams settle on existing connections. Upstream
+        # 3proxy logs this as ``00021`` (client-closed-early) on ~67% of
+        # tunnels in production. ALPN-negotiated h2 through CONNECT also
+        # exposes a Cloudflare bot-detection RST path that surfaces as
+        # ``[SSL: RECORD_LAYER_FAILURE]`` for ~10% of requests; HTTP/1.1
+        # with keep-alive sidesteps both.
+        self.http = AsyncClient(proxy=proxy, cookies=Cookies(), http2=False, **kwargs)
         self.language = language
         self.proxy = proxy
         self.captcha_solver = captcha_solver

twikit/guest/client.py

@@ -86,8 +86,10 @@ def __init__(
             )
             warnings.warn(message)
 
-        # Initialize with an isolated cookie jar to prevent cookie conflicts
-        self.http = AsyncClient(proxy=proxy, cookies=Cookies(), http2=True, **kwargs)
+        # Initialize with an isolated cookie jar to prevent cookie conflicts.
+        # ``http2=False`` mirrors the authenticated client — see comment in
+        # ``twikit/client/client.py``.
+        self.http = AsyncClient(proxy=proxy, cookies=Cookies(), http2=False, **kwargs)
         self.language = language
         self.proxy = proxy