chore(deps): Bump github.com/containerd/platforms

Bumps [github.com/containerd/platforms](https://github.com/containerd/platforms) from 1.0.0-rc.3 to 1.0.0-rc.4.
- [Release notes](https://github.com/containerd/platforms/releases)
- [Commits](containerd/platforms@v1.0.0-rc.3...v1.0.0-rc.4)

---
updated-dependencies:
- dependency-name: github.com/containerd/platforms
  dependency-version: 1.0.0-rc.4
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

go.mod

@@ -5,7 +5,7 @@ go 1.25.5
 toolchain go1.26.1
 
 require (
-	github.com/containerd/platforms v1.0.0-rc.3
+	github.com/containerd/platforms v1.0.0-rc.4
 	github.com/moby/buildkit v0.28.1
 	github.com/modelpack/model-spec v0.0.7
 	github.com/opencontainers/go-digest v1.0.0

go.sum

@@ -12,8 +12,8 @@ github.com/containerd/errdefs v1.0.0 h1:tg5yIfIlQIrxYtu9ajqY42W3lpS19XqdxRQeEwYG
 github.com/containerd/errdefs v1.0.0/go.mod h1:+YBYIdtsnF4Iw6nWZhJcqGSg/dwvV7tyJ/kCkyJ2k+M=
 github.com/containerd/log v0.1.0 h1:TCJt7ioM2cr/tfR8GPbGf9/VRAX8D2B4PjzCpfX540I=
 github.com/containerd/log v0.1.0/go.mod h1:VRRf09a7mHDIRezVKTRCrOq78v577GXq3bSa3EhrzVo=
-github.com/containerd/platforms v1.0.0-rc.3 h1:YdvwaHtrN6wHcGJ2mYRYP3Nso8OcysuqFe9Hxm1X/tI=
-github.com/containerd/platforms v1.0.0-rc.3/go.mod h1:gw0R+alP3nFQPh1L4K9bv13fRWeeyokLGLu2fKuqI10=
+github.com/containerd/platforms v1.0.0-rc.4 h1:M42JrUT4zfZTqtkUwkr0GzmUWbfyO5VO0Q5b3op97T4=
+github.com/containerd/platforms v1.0.0-rc.4/go.mod h1:lKlMXyLybmBedS/JJm11uDofzI8L2v0J2ZbYvNsbq1A=
 github.com/containerd/ttrpc v1.2.7 h1:qIrroQvuOL9HQ1X6KHe2ohc7p+HP/0VE6XPU7elJRqQ=
 github.com/containerd/ttrpc v1.2.7/go.mod h1:YCXHsb32f+Sq5/72xHubdiJRQY9inL4a4ZQrAbN1q9o=
 github.com/containerd/typeurl/v2 v2.2.3 h1:yNA/94zxWdvYACdYO8zofhrTVuQY73fFU1y++dYSw40=