Updates for TruffleRuby 23.1 (#294)

* Use the latest truffleruby+graalvm release in CI

* Update documentation to install GraalJS for TruffleRuby 23.1

.github/workflows/ci.yml

@@ -16,7 +16,7 @@ jobs:
           - "macos-12"
           - "ubuntu-20.04"
         ruby:
-          - "truffleruby+graalvm-head"
+          - "truffleruby+graalvm"
 
     name: ${{ matrix.os }} - ${{ matrix.ruby }}
     runs-on: ${{ matrix.os }}
@@ -32,7 +32,7 @@ jobs:
           bundler: latest # to get this fix: https://github.com/rubygems/rubygems/issues/6165
           bundler-cache: true
       - name: Install GraalVM JS component
-        run: gu install js
+        run: truffleruby-polyglot-get js
       - name: Compile
         run: bundle exec rake compile
       - name: Test

lib/mini_racer/truffleruby.rb

@@ -72,8 +72,7 @@ def init_unsafe(isolate, snapshot)
 
       unless Polyglot.languages.include? "js"
         raise "The language 'js' is not available, you likely need to `export TRUFFLERUBYOPT='--jvm --polyglot'`\n" \
-          "You also need to install the 'js' component with 'gu install js' on GraalVM 22.2+\n" \
-          "Note that you need TruffleRuby+GraalVM and not just the TruffleRuby standalone to use MiniRacer"
+          "You also need to install the 'js' component, see https://github.com/oracle/truffleruby/blob/master/doc/user/polyglot.md#installing-other-languages"
       end
 
       @context = Polyglot::InnerContext.new(on_cancelled: -> {