ci: add workflow_dispatch and cron jobs

both the Scorecard and the S3 gateway build actions could use from both:
* being able to run the workflow on demand
* running the workflow once a week in case there's been no new builds/PRs in the last week

.github/workflows/ossf-scorecard.yml

@@ -4,11 +4,12 @@ name: OSSF Scorecard
 on:
   # For Branch-Protection check. Only the default branch is supported. See https://github.com/ossf/scorecard/blob/main/docs/checks.md#branch-protection.
   branch_protection_rule:
+  push:
+    branches: [main]
   # To guarantee Maintained check is occasionally updated. See https://github.com/ossf/scorecard/blob/main/docs/checks.md#maintained.
   schedule:
     - cron: "0 0 * * 1"
-  push:
-    branches: [main]
+  workflow_dispatch:
 # Declare default permissions as read only.
 permissions: read-all
 jobs:

.github/workflows/s3-gateway.yml

@@ -5,6 +5,9 @@ on:
     branches: [main]
   pull_request:
     branches: [main]
+  schedule:
+    - cron: "0 0 * * 1"
+  workflow_dispatch:
 env:
   CI: true
 permissions: read-all