👷 Don't attempt to update rubygems on truffleruby / jruby

Author: pboling

.github/workflows/heads.yml

@@ -36,9 +36,9 @@ jobs:
           - f1
           - f2
         rubygems:
-          - latest
+          - default
         bundler:
-          - latest
+          - default
         ruby:
           - truffleruby+graalvm-head
           - truffleruby-head

.github/workflows/jruby-head.yml

@@ -37,9 +37,9 @@ jobs:
           - f1
           - f2
         rubygems:
-          - latest
+          - default
         bundler:
-          - latest
+          - default
         ruby:
           - jruby-head
         include:

.github/workflows/style.yml

@@ -26,7 +26,7 @@ jobs:
         bundler:
           - latest
         ruby:
-          - "2.7"
+          - ruby
     runs-on: ubuntu-latest
     steps:
       - name: Checkout