chore(deps): pin dependencies (elastic#1216)

Co-authored-by: elastic-renovate-prod[bot] <174716857+elastic-renovate-prod[bot]@users.noreply.github.com>

Author: elastic-renovate-prod[bot]

.github/workflows/copilot-setup-steps.yml

@@ -33,7 +33,7 @@ jobs:
       TF_ACC: "1"
     services:
       elasticsearch:
-        image: docker.elastic.co/elasticsearch/elasticsearch:9.0.3
+        image: docker.elastic.co/elasticsearch/elasticsearch:9.0.3@sha256:b21843a4a2efafcb0475ead137ce0a669fca412739694de833a2697f121a87b9
         env:
           discovery.type: single-node
           xpack.security.enabled: true
@@ -48,7 +48,7 @@ jobs:
           - 9200:9200
         options: --health-cmd="curl http://localhost:9200/_cluster/health" --health-interval=10s --health-timeout=5s --health-retries=10
       kibana:
-        image: docker.elastic.co/kibana/kibana:9.0.3
+        image: docker.elastic.co/kibana/kibana:9.0.3@sha256:c4c00a485fbc3619d8373f3bc74e9dd5b5a34380ef50442be4366e8fb57cd50a
         env:
           SERVER_NAME: kibana
           ELASTICSEARCH_HOSTS: http://elasticsearch:9200
@@ -60,7 +60,7 @@ jobs:
           - 5601:5601
         options: --health-cmd="curl http://localhost:5601/api/status" --health-interval=10s --health-timeout=5s --health-retries=10
       fleet:
-        image: docker.elastic.co/elastic-agent/elastic-agent:9.0.3
+        image: docker.elastic.co/elastic-agent/elastic-agent:9.0.3@sha256:c143c196d75078d1633c436fc8ab1e8c0d387d7131e3ace8bac1c1eea6d583ff
         env:
           SERVER_NAME: fleet
           FLEET_ENROLL: "1"