Add contents write permission to create release

Cherrypick obs-plugintemplate 8649be05
A GitHub Actions job has read-only permission by default and it cannot
create releases without configurations. Adding the contents write
permission enables the make-release job to create a release.

.github/workflows/main.yml

@@ -369,6 +369,8 @@ jobs:
     defaults:
       run:
         shell: bash
+    permissions:
+      contents: write
     steps:
       - name: Checkout
         uses: actions/checkout@v3