fix(gatsby-cli): lower required react version (#21522)

* chore(gatsby-cli): don't use latest react - we don't need it - use minimal supported version to decrease changes of duplicate react instances being installed in projects

* Don't update react and react-dom

* sync yarn.lock

Co-authored-by: Sidhartha Chatterjee <me@sidharthachatterjee.com>

packages/gatsby-cli/package.json

@@ -37,7 +37,7 @@
     "pretty-error": "^2.1.1",
     "progress": "^2.0.3",
     "prompts": "^2.3.0",
-    "react": "^16.12.0",
+    "react": "^16.8.0",
     "redux": "^4.0.4",
     "resolve-cwd": "^2.0.0",
     "semver": "^6.3.0",

renovate.json

@@ -11,6 +11,7 @@
   },
   "masterIssue": true,
   "rebaseStalePrs": false,
+  "excludePackageNames": ["react", "react-dom"],
   "rangeStrategy": "bump",
   "bumpVersion": null,
   "semanticCommitScope": null,

yarn.lock

@@ -18611,7 +18611,7 @@ react-typography@^0.16.19:
   resolved "https://registry.yarnpkg.com/react-typography/-/react-typography-0.16.19.tgz#5736b47961dcf6b9605b6fa38d41980db2588e28"
   integrity sha512-kV2qLEsdm0x9P4YXQEDVc88tDb4Vg0h/vdVZGgbqaRn8ERvNzV76JHUeOby3vvcUYU5MPd5Kz5DPH9Bhp4I/iw==
 
-react@^16.12.0:
+react@^16.12.0, react@^16.8.0:
   version "16.12.0"
   resolved "https://registry.yarnpkg.com/react/-/react-16.12.0.tgz#0c0a9c6a142429e3614834d5a778e18aa78a0b83"
   integrity sha512-fglqy3k5E+81pA8s+7K0/T3DBCF0ZDOher1elBFzF7O6arXJgzyu/FW+COxFvAWXJoJN9KIZbT2LXlukwphYTA==