Use ElasticSearch 6.8.23 in our local setup (#4446)

* Use ElasticSearch 6.8.23 in our local setup

This version is deployed on Ci, staging and prod.

* Add changelog entry

changelog.d/5-internal/docker-compose_es6

@@ -0,0 +1 @@
+Use ElasticSearch 6.8.23 in our local dev setups (`docker-compose`.) This is the version we use on CI, staging and prod.

deploy/dockerephemeral/docker-compose.yaml

@@ -208,13 +208,7 @@ services:
 
   elasticsearch:
     container_name: demo_wire_elasticsearch
-    build:
-      context: .
-      dockerfile_inline: |
-        FROM quay.io/wire/elasticsearch:0.0.9-amd64
-        RUN /usr/share/elasticsearch/bin/elasticsearch-plugin install x-pack -b
-        # this seems to be necessary to run X-Pack on Alpine (https://discuss.elastic.co/t/elasticsearch-failing-to-start-due-to-x-pack/85125/7)
-        RUN rm -rf /usr/share/elasticsearch/plugins/x-pack/platform/linux-x86_64
+    image: elasticsearch:6.8.23
     ulimits:
       nofile:
         soft: 65536
@@ -231,6 +225,7 @@ services:
       - "bootstrap.system_call_filter=false"
       - "JVM_OPTIONS_ES=-Xmx512m -Xms512m"
       - "discovery.type=single-node"
+      - "ELASTIC_PASSWORD=changeme"
     volumes:
       - ./docker/elasticsearch-cert.pem:/usr/share/elasticsearch/config/certs/elasticsearch-cert.pem
       - ./docker/elasticsearch-key.pem:/usr/share/elasticsearch/config/certs/elasticsearch-key.pem