security: add permissions block to workflows (#1526)

Co-authored-by: obltmachine <obltmachine@users.noreply.github.com>

Author: elastic-vault-github-plugin-prod[bot]

.github/workflows/ci-tests.yml

@@ -12,6 +12,9 @@ on:
       - "tests/**"
       - "pyproject.toml"
 
+permissions:
+  contents: read
+
 jobs:
   test:
     name: pytest

.github/workflows/ci.yml

@@ -5,6 +5,9 @@ on:
     branches: [main]
   pull_request:
     branches: [main]
+permissions:
+  contents: read
+
 jobs:
   lint-workflows:
     name: Validate GitHub Actions workflows

.github/workflows/smoke-test-install.yml

@@ -5,6 +5,9 @@ on:
     - cron: "0 6 * * *" # Daily at 06:00 UTC
   workflow_dispatch:
 
+permissions:
+  contents: none
+
 jobs:
   smoke-test:
     name: Install and compile all workflows