Revert "Merge pull request cloudfoundry#2703 from cloudfoundry/bump-r…

…uby"

Reverting for now. Breaking pipelines

This reverts commit b62ade4, reversing
changes made to 3505845.

.ruby-version

@@ -1 +1 @@
-3.0.3
+2.7.5

Gemfile.lock

@@ -636,4 +636,4 @@ DEPENDENCIES
   yajl-ruby
 
 BUNDLED WITH
-   2.2.32
+   2.1.4

spec/unit/models/runtime/stack_spec.rb

@@ -102,7 +102,7 @@ module VCAP::CloudController
                 mock_logger = double
                 allow(Steno).to receive(:logger).and_return(mock_logger)
 
-                expect(mock_logger).to receive(:warn).with('stack.populate.collision', { 'name' => 'cider', 'description' => 'cider-description' })
+                expect(mock_logger).to receive(:warn).with('stack.populate.collision', 'name' => 'cider', 'description' => 'cider-description')
 
                 Stack.populate
               end