Add logger as a dependency, drop ostruct for tests (#1010)

* Add logger as a dependency

There was a warning in ruby-head (3.4) that in Ruby 3.5 logger and
ostruct will not be built-in gems, but regular gems.

This change avoids that warning.

The ostruct dependency was be omitted.

* Lint: Style/SymbolProc

dalli.gemspec

@@ -24,4 +24,6 @@ Gem::Specification.new do |s|
     'changelog_uri' => 'https://github.com/petergoldstein/dalli/blob/main/CHANGELOG.md',
     'rubygems_mfa_required' => 'true'
   }
+
+  s.add_dependency 'logger'
 end

test/helper.rb

@@ -11,7 +11,6 @@
 
 require 'dalli'
 require 'logger'
-require 'ostruct'
 require 'securerandom'
 
 Dalli.logger = Logger.new($stdout)

test/integration/test_network.rb

@@ -15,7 +15,7 @@
 
         describe 'with a fake server' do
           it 'handle connection reset' do
-            memcached_mock(->(sock) { sock.close }) do
+            memcached_mock(lambda(&:close)) do
               dc = Dalli::Client.new('localhost:19123')
               assert_raises Dalli::RingError, message: 'No server available' do
                 dc.get('abc')
@@ -25,7 +25,7 @@
 
           it 'handle connection reset with unix socket' do
             socket_path = MemcachedMock::UNIX_SOCKET_PATH
-            memcached_mock(->(sock) { sock.close }, :start_unix, socket_path) do
+            memcached_mock(lambda(&:close), :start_unix, socket_path) do
               dc = Dalli::Client.new(socket_path)
               assert_raises Dalli::RingError, message: 'No server available' do
                 dc.get('abc')

test/protocol/test_binary.rb

@@ -1,6 +1,5 @@
 # frozen_string_literal: true
 
-require 'ostruct'
 require_relative '../helper'
 
 describe Dalli::Protocol::Binary do