fix: packages/grafana-toolkit/package.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-INFLIGHT-6095116
- https://snyk.io/vuln/SNYK-JS-MINIMATCH-3050818

packages/grafana-toolkit/package.json

@@ -91,7 +91,7 @@
     "prettier": "^2.2.1",
     "puppeteer-core": "1.18.1",
     "react-dev-utils": "^11.0.4",
-    "replace-in-file": "^4.1.0",
+    "replace-in-file": "^8.0.0",
     "replace-in-file-webpack-plugin": "^1.0.6",
     "rimraf": "^3.0.0",
     "sass": "1.27.0",