chore(ci): add OSSF Scorecard workflow (#164)

Workflow results at https://github.com/kastenhq/kubestr/security/code-scanning?query=pr%3A164+is%3Aopen

.github/workflows/ossf-scorecard.yml

@@ -0,0 +1,51 @@
+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: [ "master" ]
+  # To guarantee Maintained check is occasionally updated. See
+  # https://github.com/ossf/scorecard/blob/main/docs/checks.md#maintained
+  schedule:
+    - cron: '25 6 * * 5'
+
+# Declare default permissions as read only.
+permissions: read-all
+
+jobs:
+  analysis:
+    name: Scorecard analysis
+    runs-on: ubuntu-latest
+    permissions:
+      # Needed to upload the results to code-scanning dashboard.
+      security-events: write
+      # Needed to publish results and get a badge
+      id-token: write
+
+    steps:
+      -
+        name: "Checkout repo"
+        uses: actions/checkout@93ea575cb5d8a053eaa0ac8fa3b40d7e05a33cc8 # v3.1.0
+        with:
+          persist-credentials: false
+      -
+        name: "Run analysis"
+        uses: ossf/scorecard-action@e38b1902ae4f44df626f11ba0734b14fb91f8f86 # v2.1.2
+        with:
+          results_file: results.sarif
+          results_format: sarif
+          publish_results: true
+      -
+        # Upload the results to GitHub's code scanning dashboard.
+        name: "Upload to results to dashboard"
+        uses: github/codeql-action/upload-sarif@17573ee1cc1b9d061760f3a006fc4aac4f944fd5 # v2.2.4
+        with:
+          sarif_file: results.sarif
+      -
+        name: "Upload analysis results as 'Job Artifact'"
+        uses: actions/upload-artifact@3cea5372237819ed00197afe530f5a7ea3e805c8 # v3.1.0
+        with:
+          name: SARIF file
+          path: results.sarif
+          retention-days: 5