build(deps): bump react from 18.3.1 to 19.0.0

Bumps [react](https://github.com/facebook/react/tree/HEAD/packages/react) from 18.3.1 to 19.0.0.
- [Release notes](https://github.com/facebook/react/releases)
- [Changelog](https://github.com/facebook/react/blob/main/CHANGELOG.md)
- [Commits](https://github.com/facebook/react/commits/v19.0.0/packages/react)

---
updated-dependencies:
- dependency-name: react
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

packages/example/package.json

@@ -15,7 +15,7 @@
     "@carbon/icons-react": "^11.43.0",
     "gatsby": "^5.13.6",
     "gatsby-theme-carbon": "^4.2.2",
-    "react": "^18.3.1",
+    "react": "^19.0.0",
     "react-dom": "^18.3.1"
   }
 }

packages/gatsby-theme-carbon/package.json

@@ -19,7 +19,7 @@
   },
   "devDependencies": {
     "gatsby": "^5.13.6",
-    "react": "^18.3.1",
+    "react": "^19.0.0",
     "react-dom": "^18.3.1"
   },
   "dependencies": {

yarn.lock

@@ -10128,7 +10128,7 @@ __metadata:
     "@carbon/icons-react": "npm:^11.43.0"
     gatsby: "npm:^5.13.6"
     gatsby-theme-carbon: "npm:^4.2.2"
-    react: "npm:^18.3.1"
+    react: "npm:^19.0.0"
     react-dom: "npm:^18.3.1"
   languageName: unknown
   linkType: soft
@@ -11455,7 +11455,7 @@ __metadata:
     mkdirp: "npm:^3.0.1"
     prism-react-renderer: "npm:^2.3.1"
     prop-types: "npm:^15.8.1"
-    react: "npm:^18.3.1"
+    react: "npm:^19.0.0"
     react-dom: "npm:^18.3.1"
     react-helmet: "npm:^6.1.0"
     react-lunr: "npm:^1.1.0"
@@ -19470,12 +19470,10 @@ __metadata:
   languageName: node
   linkType: hard
 
-"react@npm:^18.3.1":
-  version: 18.3.1
-  resolution: "react@npm:18.3.1"
-  dependencies:
-    loose-envify: "npm:^1.1.0"
-  checksum: 10/261137d3f3993eaa2368a83110466fc0e558bc2c7f7ae7ca52d94f03aac945f45146bd85e5f481044db1758a1dbb57879e2fcdd33924e2dde1bdc550ce73f7bf
+"react@npm:^19.0.0":
+  version: 19.0.0
+  resolution: "react@npm:19.0.0"
+  checksum: 10/2490969c503f644703c88990d20e4011fa6119ddeca451e9de48f6d7ab058d670d2852a5fcd3aa3cd90a923ab2815d532637bd4a814add402ae5c0d4f129ee71
   languageName: node
   linkType: hard