Fix critical npm alerts

[lancewillett]

Summary

• Add npm overrides for basic-ftp and form-data in plugins/static-files-editor.
• Add an npm override for sha.js in examples/create-wp-site.
• Regenerate the affected lockfiles.

Testing

• npm ci --ignore-scripts in plugins/static-files-editor
• npm audit --audit-level=critical --json | jq ' .metadata.vulnerabilities ' in plugins/static-files-editor\n- npm ls basic-ftp form-data --all in plugins/static-files-editor\n- npm run build in plugins/static-files-editor\n- npx wp-scripts test-unit-js --runInBand --testMatch '**/*.spec.ts' in plugins/static-files-editor\n- npm ci --ignore-scripts in examples/create-wp-site\n- npm audit --audit-level=critical --json | jq ' .metadata.vulnerabilities ' in examples/create-wp-site\n- npm ls sha.js --all in examples/create-wp-site\n- node --check index.js in examples/create-wp-site\n- git diff --check