Fix build error by keeping prism below 1.5.0 for older RuboCop

Author: dvandersluis

.github/workflows/rubocop.yml

@@ -94,6 +94,11 @@ jobs:
           ruby-version: ${{ matrix.ruby }}
       - name: install rubocop from source for full specs
         run: git clone --branch $RUBOCOP_VERSION https://github.com/rubocop/rubocop.git ../rubocop
+      - name: prevent prism from breaking tests on older RuboCop
+        # FIXME: Remove when the next prism version is released.
+        # See https://github.com/rubocop/rubocop/pull/14526
+        if: matrix.rubocop == 'v1.72.1'
+        run: cd ../rubocop && sed -i "s/gem 'prism'.*$/gem 'prism', '< 1.5.0'/" Gemfile
       - name: install rubocop dependencies
         run: cd ../rubocop && bundle install --jobs 3 --retry 3
       - name: install dependencies