Fix .gitignore: stop tracking ignored files

backend/lib/openzeppelin-contracts/scripts/release/workflow/integrity-check.sh

@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+CHECKSUMS="$RUNNER_TEMP/checksums.txt"
+
+# Extract tarball content into a tmp directory
+tar xf "$TARBALL" -C "$RUNNER_TEMP"
+
+# Move to extracted directory
+cd "$RUNNER_TEMP/package"
+
+# Checksum all Solidity files
+find . -type f -name "*.sol" | xargs shasum > "$CHECKSUMS"
+
+# Back to directory with git contents
+cd "$GITHUB_WORKSPACE/contracts"
+
+# Check against tarball contents
+shasum -c "$CHECKSUMS"