Fix Ruby 3.4 compatibility issues in tests

- PrerenderError test: Handle absolute vs relative paths in backtraces
- Utils test: Handle new hash syntax format ({a: "value"} vs {:a=value})

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

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

Author: justin808

spec/react_on_rails/prender_error_spec.rb

@@ -65,9 +65,8 @@ module ReactOnRails
         it "shows truncated backtrace with notice" do
           message = expected_error.message
           expect(message).to include(err.inspect)
-          expect(message).to include(
-            "spec/react_on_rails/prender_error_spec.rb:20:in `block (2 levels) in <module:ReactOnRails>'"
-          )
+          # Ruby 3.4+ shows absolute paths, so match the end of the path
+          expect(message).to include("prender_error_spec.rb:20:in `block (2 levels) in <module:ReactOnRails>'")
           expect(message).to include("The rest of the backtrace is hidden")
         end
       end

spec/react_on_rails/utils_spec.rb

@@ -463,9 +463,9 @@ def mock_dev_server_running
 
           it "trims handles a hash" do
             s = { a: "1234567890" }
-            expect(described_class.smart_trim(s, 9)).to eq(
-              "{:a=#{Utils::TRUNCATION_FILLER}890\"}"
-            )
+            result = described_class.smart_trim(s, 9)
+            # Ruby 3.4+ changed hash syntax, so be flexible about the format
+            expect(result).to match(/\{(:a=|a: ")#{Regexp.escape(Utils::TRUNCATION_FILLER)}90"\}/)
           end
         end
       end