Explicitly use bundler 2.7 on Ruby 4 CI #572

Job	Run time
docker_build / build	27s
test / set_matrix	5s
lint / lint	47s
test / ruby 3.3 \| rails 8.0.4 \| Rails 8.0 + Ruby 3.3	4m 29s
test / ruby 4.0 \| rails 8.1.1 \| Ruby 4	4m 2s
test / ruby 3.4 \| rails 8.0.4 \| esbuild	4m 4s
test / ruby 3.4 \| rails 7.2.3 \| Rails 7.2 + Propshaft, esbuild	4m 4s
test / ruby 3.4 \| rails 8.1.1 \| API	2m 25s
test / ruby 3.4 \| rails 8.1.1	4m 7s
test / ruby 3.4 \| rails 8.0.4 ViewComponent 3	4m 0s
test / ruby 3.4 \| rails 8.1.1 \| esbuild	4m 8s
test / ruby 3.2 \| rails 8.0.4 \| Solr 8.11.2 and Ruby 3.2	3m 37s
	36m 15s

Provide feedback