Add OSSF scorecard workflow

.github/workflows/build-and-sign-eif.yaml

@@ -5,7 +5,7 @@ on:
     branches:
       - main
     paths:
-      - ".github/workflows/**"
+      - ".github/workflows/build-and-sign-eif.yaml"
       - "enclave/**"
 
 jobs:

.github/workflows/scorecard.yaml

@@ -0,0 +1,44 @@
+name: Scorecard supply-chain security
+
+on:
+  push:
+    branches:
+      - main
+
+# Declare default permissions as read only.
+permissions: read-all
+
+jobs:
+  analysis:
+    name: Scorecard analysis
+    runs-on: ubuntu-latest
+    permissions:
+      security-events: write
+      id-token: write
+      contents: read
+      actions: read
+
+    steps:
+      - name: "Checkout code"
+        uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
+        with:
+          persist-credentials: false
+
+      - name: "Run analysis"
+        uses: ossf/scorecard-action@0864cf19026789058feabb7e87baa5f140aac736 # v2.3.1
+        with:
+          results_file: results.sarif
+          results_format: sarif
+          publish_results: false
+
+      - name: "Upload artifact"
+        uses: actions/upload-artifact@97a0fba1372883ab732affbe8f94b823f91727db # v3.pre.node20
+        with:
+          name: SARIF file
+          path: results.sarif
+          retention-days: 5
+
+      - name: "Upload to code-scanning"
+        uses: github/codeql-action/upload-sarif@v3
+        with:
+          sarif_file: results.sarif