Bump lodash from 4.17.11 to 4.17.21 in /tools/nf-gen-ts

Bumps [lodash](https://github.com/lodash/lodash) from 4.17.11 to 4.17.21.
- [Release notes](https://github.com/lodash/lodash/releases)
- [Commits](lodash/lodash@4.17.11...4.17.21)

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

tools/nf-gen-ts/package-lock.json

@@ -70,7 +70,7 @@
     "commander": "^2.14.1",
     "common-tags": "^1.7.2",
     "find-up": "^3.0.0",
-    "lodash": "^4.17.5",
+    "lodash": "^4.17.21",
     "markdown-toc": "^1.2.0",
     "mkdirp": "^0.5.1",
     "option-t": "^16.1.1",