[ServiceBus] Document aiohttp>=3.14.0 recommendation for AmqpOverWebsocket (#44028)

[pranz1996]

Summary

Documents that azure-servicebus users on the async AmqpOverWebsocket transport should use aiohttp>=3.14.0. This resolves customer issue #44028 ("Service Bus WebSocket connection breaks after 15 seconds"), which is an upstream aiohttp bug, not an azure-servicebus defect.

Root cause

On aiohttp < 3.14.0, the WebSocket heartbeat timer was only reset inside receive() after a full message was read. During long message processing (no socket read for ~15s), aiohttp sends its PING, the PONG is not serviced within the ~5s window, and aiohttp closes the transport at ~15s -- surfacing as ErrorCondition.SocketError: "Cannot write to closing transport".

Fixed upstream by aio-libs/aiohttp#12030, which moves the heartbeat reset to the protocol-level data_received callback. Shipped in aiohttp 3.14.0 (2026-06-01) and was not backported to 3.13.x.

Validation (definitive bisect)

Reporter's exact pattern (default receiver, prefetch_count=0, AutoLockRenewer, sleep 14-17s/msg) against a live Standard namespace, unchanged SDK, varying only aiohttp:

aiohttp	Result
3.13.5	BROKE (reproduces #44028)
3.14.1	OK

An SDK-side keep-alive interval cap was prototyped and empirically invalidated (still broke on aiohttp 3.13.5), so no code change is made -- this is docs-only.

Changes

• CHANGELOG.md: added an "Other Changes" note under 7.15.0 (Unreleased) recommending aiohttp>=3.14.0 and describing the symptom + upstream fix.

Why docs-only

aiohttp is an optional, lazily-imported dependency (no version floor declared). The repo convention is to document aiohttp version behavior in the CHANGELOG rather than add runtime version nagging (see azure-core and azure-eventhub changelog precedents).

Testing

No code changed; no test impact. CHANGELOG-only.

Related Work

• GitHub Issue: Service Bus WebSocket connection breaks after 15 seconds #44028 -- Service Bus WebSocket connection breaks after 15 seconds
• Upstream fix: Fix/ws heartbeat reset on data aio-libs/aiohttp#12030

[Copilot]

Pull request overview

Documents the aiohttp>=3.14.0 recommendation for async Service Bus WebSocket users affected by upstream heartbeat failures.

Changes:

• Adds the recommendation and links the upstream fix and customer issue.
• Describes the resulting socket error.

[SwayGom]

Approving. This is a well-scoped, documentation-only CHANGELOG update with no code, API, or behavior impact.

The aiohttp>=3.14.0 recommendation is correctly scoped to Python 3.10+, and the explicit Python 3.9 caveat accurately explains that users must upgrade Python before they can install a release containing the fix. That also resolves the earlier reviewer concern. The entry is placed consistently under the unreleased Other Changes section, and all checks are green. LGTM.