dep: bump rubocop, rubocop-rspec and solargraph

Can't show this merge request because the source branch dependabot-bundler-rubocop-and-rubocop-rspec-and-solargraph-1.6.1 is missing from project georgekoltsov-multiple-projects-test-4/imported-project-ef029319134ab099. Close this merge request or update the source branch.