Upgrade gRPC to 1.65.2

Need a newer version for compatibility with Ruby 3.3.5.

gRPC requires Ruby 3.x starting with version 1.66.0, so
pick the newest version before 1.66.0.

fluent-plugin-google-cloud.gemspec

@@ -13,7 +13,7 @@ Gem::Specification.new do |gem|
   gem.version       = '0.13.2'
   gem.authors       = ['Stackdriver Agents Team']
   gem.email         = ['[email protected]']
-  gem.required_ruby_version = Gem::Requirement.new('>= 2.6')
+  gem.required_ruby_version = Gem::Requirement.new('>= 2.7')
 
   gem.files         = Dir['**/*'].keep_if { |file| File.file?(file) }
   gem.test_files    = gem.files.grep(/^(test)/)
@@ -28,8 +28,8 @@ Gem::Specification.new do |gem|
   gem.add_runtime_dependency 'googleauth', '1.3.0'
   gem.add_runtime_dependency 'google-cloud-logging', '2.3.2'
   gem.add_runtime_dependency 'google-cloud-monitoring-v3', '0.10.0'
-  gem.add_runtime_dependency 'google-protobuf', '3.22.1'
-  gem.add_runtime_dependency 'grpc', '1.53.0'
+  gem.add_runtime_dependency 'google-protobuf', '3.25.5'
+  gem.add_runtime_dependency 'grpc', '1.65.2'
   gem.add_runtime_dependency 'json', '2.6.3'
   gem.add_runtime_dependency 'opencensus', '0.5.0'
   gem.add_runtime_dependency 'opencensus-stackdriver', '0.4.1'