fix: grant pull-requests write permission in release workflow

@semantic-release/github's success step fetches commits from PRs
referenced in release commit messages. Without explicit permissions,
the GITHUB_TOKEN lacks pull_requests=read scope, causing 404 errors
on PRs from the upstream repo's history.

Ticket: DX-916

Author: ericcrosson-bitgo

.github/workflows/release.yml

@@ -18,6 +18,10 @@ jobs:
   release:
     name: Release
     runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      issues: write
+      pull-requests: write
 
     steps:
       - name: Release