fix(ci): Grant statuses: write to changelog-preview caller

Upstream getsentry/craft/changelog-preview.yml declares
permissions.statuses: write at the job level unconditionally, so the
caller must grant it or workflow validation fails with:

  "The nested job 'preview' is requesting 'statuses: write', but is
  only allowed 'statuses: none'."

Matches the pattern in sentry-cocoa, sentry-dotnet, sentry-go.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: antonis

.github/workflows/changelog-preview.yml

@@ -11,6 +11,7 @@ on:
 permissions:
   contents: read
   pull-requests: write
+  statuses: write
 
 jobs:
   changelog-preview: