Update keyword arguments for Ruby 3.0

[sethboyles]

Pulled this out of #2623 to avoid having long living branches and merge conflicts with them.

See here for why this needs to be changed: https://www.ruby-lang.org/en/news/2019/12/12/separation-of-positional-and-keyword-arguments-in-ruby-3-0/

[philippthun]

I don't get where these kwargs are coming from...

[sethboyles]

They are used here:

cloud_controller_ng/lib/cloud_controller/blobstore/fog/fog_client.rb

Lines 41 to 49 in 5ee5e06

	def download_from_blobstore(source_key, destination_path, mode: nil)
	FileUtils.mkdir_p(File.dirname(destination_path))
	File.open(destination_path, 'wb') do |file|
	(@cdn || files).get(partitioned_key(source_key)) do |*chunk|
	file.write(chunk[0])
	end
	file.chmod(mode) if mode
	end
	end

Due to the multi-layer wrapping of these classes, each method needs to conform to the same signature

[sethboyles]

See here for where they get wrapped:

cloud_controller_ng/lib/cloud_controller/blobstore/client_provider.rb

Lines 28 to 56 in 4a23a41

	def provide_fog(options, directory_key, root_dir)
	cdn_uri = HashUtils.dig(options[:cdn], :uri)
	cdn = CloudController::Blobstore::Cdn.make(cdn_uri)
	client = FogClient.new(
	connection_config: options.fetch(:fog_connection),
	directory_key: directory_key,
	cdn: cdn,
	root_dir: root_dir,
	min_size: options[:minimum_size],
	max_size: options[:maximum_size],
	storage_options: options[:fog_aws_storage_options]
	)
	logger = Steno.logger('cc.blobstore')
	# work around https://github.com/fog/fog/issues/3137
	# and Fog raising an EOFError SocketError intermittently
	# and https://github.com/fog/fog-aws/issues/264
	# and https://github.com/fog/fog-aws/issues/265
	# and intermittent GCS blobstore download errors
	errors = [Excon::Errors::BadRequest, Excon::Errors::SocketError, SystemCallError,
	Excon::Errors::InternalServerError, Excon::Errors::ServiceUnavailable,
	Google::Apis::ServerError, Google::Apis::TransmissionError
	]
	retryable_client = RetryableClient.new(client: client, errors: errors, logger: logger)
	Client.new(ErrorHandlingClient.new(SafeDeleteClient.new(retryable_client, root_dir)))
	end