chore(ci): grant publish permissions

Adds explicit write permissions for contents, packages, id-token, and attestations in the CI workflow.
Enables publishing packages and acquiring OIDC tokens/attestations during runs.
Prevents permission-related failures when attempting to publish.

Author: SakuraIsayeki

.github/workflows/nuget-publish.yml

@@ -1,5 +1,11 @@
 name: Publish NuGet packages
 
+permissions:
+  contents: write
+  packages: write
+  id-token: write
+  attestations: write
+  
 # Controls when the action will run. 
 on:
   push: