fix(core): support ipx 4 in the dev middleware

[BleedingDev]

IPX programmatic API

Why the change

IPX 4 replaces the dev middleware factory, so the image plugin must support its new handler while retaining IPX 3 compatibility.

Special things to note

• The peer range is bounded to IPX 3 and 4 and explicitly permits v4 prereleases.
• Real Rsbuild dev-server requests return 48px WebP images on both installed IPX 4 and the IPX 3 alias; all 12 unit suites pass with 107 tests and 13 existing skips.
• Core/react CJS/ESM and declaration builds and 90 Biome checks pass; current-head upstream workflows require approval.

Change outline

 peerDependencies.ipx
-  >=3.0.3
+  ^3.0.3 || ^4.0.0-0

 dev middleware
-  createIPXNodeServer(ipx)
+  createIPXNodeHandler(ipx) when available
+  otherwise createIPXNodeServer(ipx)