chore: bump rubocop to ~> 1.86 and rubocop-rspec to ~> 3.9

Bumps the linting toolchain:
- rubocop: 1.72.2 (pinned exact) -> ~> 1.86
- rubocop-rspec: ~> 3.6 -> ~> 3.9

Loosens rubocop to a pessimistic constraint so it can pick up patch and
minor bumps without another Gemfile change.

The newer rubocop / rubocop-rspec set surfaces ten new offences. Nine of
them are two cops misfiring on `spec/spec_helper.rb`, which is integration
infrastructure (boots Typesense via docker-compose) rather than an
example file:

- `RSpec/Output` flags the `puts`/`print` calls that report
  docker-compose startup progress to the operator. They are not
  assertions on stdout, so the cop's intent does not apply.
- `Naming/PredicateMethod` flags `ensure_typesense_running`, which
  returns a boolean but has heavy side effects (boots a docker
  container); renaming it to `ensure_typesense_running?` would be
  misleading.

Both cops are excluded only for `spec/spec_helper.rb`. The tenth offence
was a real but trivial `Style/HashAsLastArrayItem` /
`Layout/SpaceInsideHashLiteralBraces` in `collection_spec.rb`, fixed by
autocorrect.

Verified: `bundle exec rubocop` reports 97 files, 0 offences. Full RSpec
suite is unchanged at 151 / 1 / 27 (the single pre-existing `truncate_len`
integration failure on master remains, unrelated).

Author: erimicel

.rubocop.yml

@@ -47,5 +47,13 @@ RSpec/ExampleLength:
 RSpec/MultipleExpectations:
   Enabled: false
 
+RSpec/Output:
+  Exclude:
+    - spec/spec_helper.rb
+
+Naming/PredicateMethod:
+  Exclude:
+    - spec/spec_helper.rb
+
 Style/HashSyntax:
   Enabled: false # We still want to support older versions of Ruby

Gemfile

@@ -15,8 +15,8 @@ gem 'rake', '~> 13.0'
 gem 'rspec', '~> 3.9'
 gem 'rspec_junit_formatter', '~> 0.4'
 gem 'rspec-legacy_formatters', '~> 1.0' # For codecov formatter
-gem 'rubocop', '1.72.2'
-gem 'rubocop-rspec', '~> 3.6', require: false
+gem 'rubocop', '~> 1.86'
+gem 'rubocop-rspec', '~> 3.9', require: false
 gem 'simplecov', '~> 0.18'
 gem 'timecop', '~> 0.9'
 gem 'webmock', '~> 3.8'

spec/typesense/collection_spec.rb

@@ -52,7 +52,7 @@
     it 'updates the specified collection' do
       update_schema = {
         'fields' => [
-          'name' => 'field', 'drop' => true
+          { 'name' => 'field', 'drop' => true }
         ]
       }
       stub_request(:patch, Typesense::ApiCall.new(typesense.configuration).send(:uri_for, '/collections/companies', typesense.configuration.nodes[0]))