chore: re-enable harden-runner in nightly build

Author: kaushalnavneet

.github/workflows/nightly-build.yml

@@ -36,10 +36,10 @@ jobs:
       id-token: write
 
     steps:
-      # - name: Harden runner
-      #   uses: step-security/harden-runner@f4a75cfd619ee5ce8d5b864b0d183aff3c69b55a # v2.13.1
-      #   with:
-      #     egress-policy: audit
+      - name: Harden runner
+        uses: step-security/harden-runner@f4a75cfd619ee5ce8d5b864b0d183aff3c69b55a # v2.13.1
+        with:
+          egress-policy: audit
 
       - name: Checkout repository
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2