build: target Compose Multiplatform 1.12.0-rc01

[kdroidFilter]

Why

Apps running Compose Multiplatform 1.12 crash on the current artifacts:

java.lang.NoSuchMethodError: 'org.jetbrains.skia.Data org.jetbrains.skia.Image.encodeToData$default(
    org.jetbrains.skia.Image, org.jetbrains.skia.EncodedImageFormat, int, int, java.lang.Object)'
    at ComposableIconUtils.renderComposableToPngBytes(ComposableIconUtils.kt:101)

Skiko 0.150.1 (shipped with Compose 1.12) added a pngCompressionLevel parameter to
Image.encodeToData, so the synthetic $default bridge we were compiled against no longer exists.
The call site is source-compatible (all extra params have defaults) — only a recompile against 1.12
is needed.

Change

• compose 1.11.1 → 1.12.0-rc01 (skiko 0.150.1)

No source changes were required in composenativetray or composenativetray-app.

Verified

• ./gradlew build (compile + tests + ktlint + detekt) green on both modules
• :demo:compileKotlinJvm green
• Tray icon rendering (the failing Skia path) runs fine at runtime against skiko 0.150.1

Note

Downstream, nucleus.decorated-window-tao 2.4.4 is still compiled against Compose 1.11 and fails
with a matching NoSuchMethodError on CanvasLayersComposeScene, so a Nucleus release built
against 1.12 is required before the demo/TrayApp path works end to end. Nothing to fix here.

When 1.12.0 stable ships, this is a one-line version bump.