Update Couchbase image tag used in integration tests

[mhalbritter]

Right now, we use Couchbase 6.5.1 for our integration tests. This image doesn't support the ARM architecture, which falls back to emulation on M1 macs, which is very slow. It looks like the Couchbase team added ARM support starting with 7.1: https://hub.docker.com/_/couchbase/tags?page=1&name=7.1

Consider updating the integration tests to use at least 7.1 for ARM support.

[mhalbritter]

It's so slow that the test fails:

CouchbaseAutoConfigurationIntegrationTests > initializationError FAILED
    org.testcontainers.containers.ContainerLaunchException at GenericContainer.java:349
        Caused by: org.rnorth.ducttape.RetryCountExceededException at Unreliables.java:88
            Caused by: org.testcontainers.containers.ContainerLaunchException at GenericContainer.java:553
                Caused by: org.testcontainers.containers.ContainerLaunchException at HttpWaitStrategy.java:320
                    Caused by: org.rnorth.ducttape.TimeoutException at Unreliables.java:54
                        Caused by: java.lang.RuntimeException at HttpWaitStrategy.java:312
                            Caused by: java.net.SocketException at NioSocketImpl.java:323