Revert react version for compatibility with labextension.

Author: fleming79

package.json

@@ -100,7 +100,7 @@
         "@lumino/commands": "^2.3.1",
         "@lumino/disposable": "^2.1.3",
         "@lumino/widgets": "^2.5.0",
-        "react": "^19.1.0",
+        "react": "18.3.1",
         "webpack": "^5.99.9"
     },
     "devDependencies": {

yarn.lock

@@ -4338,7 +4338,7 @@ __metadata:
     mkdirp: ^3.0.1
     npm-run-all: ^4.1.5
     prettier: ^3.0.0
-    react: ^19.1.0
+    react: 18.3.1
     rimraf: ^6.0.1
     stylelint: ^15.10.1
     stylelint-config-recommended: ^13.0.0
@@ -5953,7 +5953,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"react@npm:>=17.0.0 <19.0.0, react@npm:^18.2.0":
+"react@npm:18.3.1, react@npm:>=17.0.0 <19.0.0, react@npm:^18.2.0":
   version: 18.3.1
   resolution: "react@npm:18.3.1"
   dependencies:
@@ -5962,13 +5962,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"react@npm:^19.1.0":
-  version: 19.1.0
-  resolution: "react@npm:19.1.0"
-  checksum: c0905f8cfb878b0543a5522727e5ed79c67c8111dc16ceee135b7fe19dce77b2c1c19293513061a8934e721292bfc1517e0487e262d1906f306bdf95fa54d02f
-  languageName: node
-  linkType: hard
-
 "read-pkg-up@npm:^8.0.0":
   version: 8.0.0
   resolution: "read-pkg-up@npm:8.0.0"