Make sure Faraday 2.x always has an adapter set

lib/rabbitmq/http/client.rb

@@ -447,7 +447,7 @@ def initialize_connection(endpoint, options = {})
         user     = uri.user     || options.delete(:username) || "guest"
         password = uri.password || options.delete(:password) || "guest"
         options = options.merge(:url => uri.to_s)
-        adapter = options.delete(:adapter) || Faraday.default_adapter
+        adapter = options.delete(:adapter) || Faraday.default_adapter || :httpclient
 
         @connection = Faraday.new(options) do |conn|
           conn.request    :authorization, :basic, user, password

rabbitmq_http_api_client.gemspec

@@ -21,6 +21,6 @@ Gem::Specification.new do |gem|
   gem.add_dependency    'addressable', '~> 2.7'
   gem.add_dependency    'hashie', '~> 4.1'
   gem.add_dependency    'multi_json', '~> 1.15'
-  gem.add_dependency    'faraday', '~> 2.0'
+  gem.add_dependency    'faraday', '~> 2.9'
   gem.add_dependency    'faraday-follow_redirects', '~> 0.3'
 end

spec/integration/api_endpoints_spec.rb

@@ -488,6 +488,7 @@ def await_event_propagation
     let(:queue_name) { "httpdeclared" }
 
     it "declares a queue" do
+      @channel.queue_delete(queue_name)
       subject.declare_queue("/", queue_name, durable: false, auto_delete: true)
 
       q = @channel.queue(queue_name, durable: false, auto_delete: true)