v1.20251225.0

What's Changed

• throw appropriate signal.reason on empty by @anonrig in https://github.com/cloudflare/workerd/pull/5762
• Convert IdentityTransformStream to use state machine with autogate by @jasnell in https://github.com/cloudflare/workerd/pull/5763
• improve streams wpt coverage by @anonrig in https://github.com/cloudflare/workerd/pull/5759
• throw appropriate error for non-byob stream mode by @anonrig in https://github.com/cloudflare/workerd/pull/5748
• Fix TextEncoderStream surrogate pair handling across chunks by @anonrig in https://github.com/cloudflare/workerd/pull/5680
• fix streams wpt piping/pipe-through.any.js by @anonrig in https://github.com/cloudflare/workerd/pull/5745
• fix streams backpressure condition check by @anonrig in https://github.com/cloudflare/workerd/pull/5758
• Add @all-autogates test variant to wd_test by @danlapid in https://github.com/cloudflare/workerd/pull/5760

Full Changelog: https://github.com/cloudflare/workerd/compare/v1.20251224.0...v1.20251225.0