Update vendored sarama version to 1.23.1

[faec]

The motivation for this update is to support the IsolationFlag configuration parameter in #12850, but this PR is just a version bump with no functional changes.

[ph]

Took a look a the Sarama code,

LGTM

// IsolationLevel support 2 mode:
// 	- use `ReadUncommitted` (default) to consume and return all messages in message channel
//	- use `ReadCommitted` to hide messages that are part of an aborted transaction

[ph]

I've looked at the failing test and its definively not related to this change.

11:26:31 ok  	github.com/elastic/beats/metricbeat/module/rabbitmq/queue	1.105s	coverage: 76.5% of statements
11:26:37 command [go test -race -tags integration -cover -coverprofile /tmp/gotestcover-228237016 github.com/elastic/beats/metricbeat/module/redis/keyspace]: exit status 1
11:26:37 --- FAIL: TestFetch (3.08s)
11:26:37     keyspace_integration_test.go:48: redis/keyspace event: []
11:26:37     keyspace_integration_test.go:51: 
11:26:37         	Error Trace:	keyspace_integration_test.go:51
11:26:37         	Error:      	Should be true
11:26:37         	Test:       	TestFetch
11:26:37 panic: runtime error: index out of range [recovered]
11:26:37 	panic: runtime error: index out of range
11:26:37 
11:26:37 goroutine 18 [running]:
11:26:37 testing.tRunner.func1(0xc000212f00)
11:26:37 	/usr/local/go/src/testing/testing.go:830 +0x69d
11:26:37 panic(0xb96900, 0x1159700)
11:26:37 	/usr/local/go/src/runtime/panic.go:522 +0x1b5
11:26:37 github.com/elastic/beats/metricbeat/module/redis/keyspace.TestFetch(0xc000212f00)
11:26:37 	/go/src/github.com/elastic/beats/metricbeat/module/redis/keyspace/keyspace_integration_test.go:53 +0xa8e
11:26:37 testing.tRunner(0xc000212f00, 0xc522e8)
11:26:37 	/usr/local/go/src/testing/testing.go:865 +0x164
11:26:37 created by testing.(*T).Run