feat(security): Add provenance (#650)

* Enable provenance in package.json

* Add necessary permissions to the release workflow

.github/workflows/release.yml

@@ -6,6 +6,13 @@ name: Release
       - next
       - beta
       - v*.x
+# These are recommended by the semantic-release docs: https://github.com/semantic-release/npm#npm-provenance
+permissions:
+    contents: write # to be able to publish a GitHub release
+    issues: write # to be able to comment on released issues
+    pull-requests: write # to be able to comment on released pull requests
+    id-token: write # to enable use of OIDC for npm provenance
+
 jobs:
   release:
     name: release

package.json

@@ -2,7 +2,8 @@
   "name": "@octokit/fixtures",
   "version": "0.0.0-development",
   "publishConfig": {
-    "access": "public"
+    "access": "public",
+    "provenance": true
   },
   "description": "Fixtures for all the octokittens",
   "main": "index.js",