Use default disk size on test runners

Author: donoghuc

.buildkite/scripts/build-pipeline/generate-steps.py

@@ -65,8 +65,7 @@ def generate_steps_for_main_branch(versions) -> list:
             "provider": "gcp",
             "machineType": "n2-standard-4",
             "imageProject": "elastic-images-prod",
-            "image": "family/platform-ingest-logstash-multi-jdk-ubuntu-2204",
-            "diskSizeGb": 120
+            "image": "family/platform-ingest-logstash-multi-jdk-ubuntu-2204"
         },
         "steps": []}
 

.buildkite/scripts/pull-request-pipeline/generate-steps.py

@@ -63,8 +63,7 @@ def make_matrix_version_key(branch: str) -> str:
             "provider": "gcp",
             "machineType": "n2-standard-4",
             "imageProject": "elastic-images-prod",
-            "image": "family/platform-ingest-logstash-multi-jdk-ubuntu-2204",
-            "diskSizeGb": 120
+            "image": "family/platform-ingest-logstash-multi-jdk-ubuntu-2204"
         },
         "steps": []}