Fix Shakapacker version mismatch in react_on_rails_pro

Update Shakapacker from 8.0.0 to 9.1.0 in:
- react_on_rails_pro/Gemfile.development_dependencies
- react_on_rails_pro/spec/execjs-compatible-dummy/package.json

This fixes the version mismatch error in CI where the gem was 8.0.0
but the node package was detected as 9.1.0.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: justin808

react_on_rails_pro/Gemfile.development_dependencies

@@ -7,7 +7,7 @@ ruby '3.3.7'
 
 gem "react_on_rails", path: "../"
 
-gem "shakapacker", "8.0.0"
+gem "shakapacker", "9.1.0"
 gem "bootsnap", require: false
 gem "rails", "~> 7.1"
 gem "puma", "~> 6"

react_on_rails_pro/spec/execjs-compatible-dummy/package.json

@@ -30,7 +30,7 @@
     "react": "^18.3.1",
     "react-dom": "^18.3.1",
     "react-on-rails": "link:.yalc/react-on-rails",
-    "shakapacker": "8.0.0",
+    "shakapacker": "9.1.0",
     "style-loader": "^4.0.0",
     "terser-webpack-plugin": "5",
     "webpack": "5",

react_on_rails_pro/spec/execjs-compatible-dummy/yarn.lock

@@ -3657,13 +3657,14 @@ setprototypeof@1.2.0:
   resolved "https://registry.yarnpkg.com/setprototypeof/-/setprototypeof-1.2.0.tgz#66c9a24a73f9fc28cbe66b09fed3d33dcaf1b424"
   integrity sha512-E5LDX7Wrp85Kil5bhZv46j8jOeboKq5JMmYM3gVGdGH8xFpPWXUMsNrlODCrkoxMEeNi/XZIwuRvY4XNwYMJpw==
 
-shakapacker@8.0.0:
-  version "8.0.0"
-  resolved "https://registry.yarnpkg.com/shakapacker/-/shakapacker-8.0.0.tgz#f29537c19078af7318758c92e7a1bca4cee96bdd"
-  integrity sha512-HCdpITzIKXzGEyUWQhKzPbpwwOsgTamaPH+0kXdhM59VQxZ3NWnT5cL3DlJdAT3sGsWCJskEl3eMkQlnh9DjhA==
+shakapacker@9.1.0:
+  version "9.1.0"
+  resolved "https://registry.npmjs.org/shakapacker/-/shakapacker-9.1.0.tgz#6d63c4d27b9358073dd8fc3c6e79252b96d36a36"
+  integrity sha512-PL0DuzNLFJMwr5s908ImMuvejmC20WuDa7EfAPpPFU1pM5U8cPqqC4kwSdXFLfVU0Or/UqeegNyIB1sGBdSPiw==
   dependencies:
     js-yaml "^4.1.0"
     path-complete-extname "^1.0.0"
+    webpack-merge "^5.8.0"
 
 shallow-clone@^3.0.0:
   version "3.0.1"
@@ -4050,9 +4051,9 @@ webpack-dev-server@4:
     webpack-dev-middleware "^5.3.4"
     ws "^8.13.0"
 
-webpack-merge@5, webpack-merge@^5.7.3:
+webpack-merge@5, webpack-merge@^5.7.3, webpack-merge@^5.8.0:
   version "5.10.0"
-  resolved "https://registry.yarnpkg.com/webpack-merge/-/webpack-merge-5.10.0.tgz#a3ad5d773241e9c682803abf628d4cd62b8a4177"
+  resolved "https://registry.npmjs.org/webpack-merge/-/webpack-merge-5.10.0.tgz#a3ad5d773241e9c682803abf628d4cd62b8a4177"
   integrity sha512-+4zXKdx7UnO+1jaN4l2lHVD+mFvnlZQP/6ljaJVb4SZiwIKeUnrT5l0gkT8z+n4hKpC+jpOv6O9R+gLtag7pSA==
   dependencies:
     clone-deep "^4.0.1"