chore(deps): bump oven/bun from 1.3.14-alpine to 1.4.0-alpine

[dependabot]

Bumps oven/bun from 1.3.14-alpine to 1.4.0-alpine.

[Coriou]

Holding this bump — the pinned image ships a known streaming regression that hits this project's hottest path.

Why: oven-sh/bun#39846 — under Bun 1.4.0 a streamed response can be silently lost with ECONNRESET when the peer closes while a response stream is in flight (maintainer repro ~1/300 iterations; real-world SSE relay workloads reported far higher loss rates).

up-redis serves every PubSub subscription as a long-lived SSE relay (streamSSE), and its pattern-subscribe path runs a hand-rolled RESP client over a plain socket — both sit directly on the affected usockets code.

Evidence the fix isn't in this tag: fix PR oven-sh/bun#39860 was merged 2026-08-21, after the v1.4.0 tag (published 2026-08-20); the maintainers confirm "the fix is not in 1.4.0". No v1.4.1 exists as of 2026-08-26.

Plan: keeping this PR open — when Dependabot re-targets it at ≥ 1.4.1 (or we bump manually once it's out) it lands immediately. Everything else in 1.3.14 → 1.4.0 reviewed clean against our usage (Bun.redis lifecycle fixes align with our dedicated-connection model; no error-code matching, no setKeepAlive, drain bounded by shutdown timeout).

[dependabot]

Superseded by #29.