Reduce JRuby Tests (#45)

These tests are time consuming and unnecessarily flaky at times. As,
GitHub actions has no support for running failed jobs only, it becomes
too time consuming to get these tests passing.

Author: avmnu-sng

.github/workflows/jruby-ruby-project.yml

@@ -11,15 +11,15 @@ concurrency:
 
 jobs:
   main:
-    name: ruby-${{ matrix.ruby }} rspec-${{ matrix.rspec }} simplecov-${{ matrix.simplecov }}
+    name: ${{ matrix.ruby }} rspec-${{ matrix.rspec }} simplecov-${{ matrix.simplecov }}
     runs-on: ubuntu-latest
 
     strategy:
       fail-fast: false
       matrix:
-        ruby: [ 'jruby-9.2.10.0', 'jruby-9.2.19.0', 'jruby-9.3.0.0' ]
-        rspec: [ '3.6.0', '3.7.0', '3.8.0', '3.9.0', '3.10.0' ]
-        simplecov: [ '0.12.0', '0.13.0', '0.14.0', '0.15.0', '0.16.0', '0.17.0', '0.18.0', '0.19.0', '0.20.0', '0.21.0' ]
+        ruby: [ 'jruby-9.2.10.0', 'jruby-9.2.14.0', 'jruby-9.2.19.0', 'jruby-9.3.0.0', 'jruby-head' ]
+        rspec: [ '3.10.0' ]
+        simplecov: [ '0.21.0' ]
 
     steps:
       - name: Checkout

lib/rspec_tracer.rb

@@ -130,6 +130,8 @@ def simplecov?
     private
 
     def valid_jruby_opts?
+      require 'jruby'
+
       return true if Java::OrgJruby::RubyInstanceConfig.FULL_TRACE_ENABLED &&
         JRuby.runtime.object_space_enabled?