chore: add Data Engineering Agent client metadata and requirements (#14283)

Author: xtan999

.github/CODEOWNERS

@@ -87,6 +87,7 @@
 /connectgateway/**/*                   @GoogleCloudPlatform/connectgateway @GoogleCloudPlatform/python-samples-reviewers @GoogleCloudPlatform/cloud-samples-reviewers
 /dlp/**/*                              @GoogleCloudPlatform/googleapis-dlp @GoogleCloudPlatform/python-samples-reviewers @GoogleCloudPlatform/cloud-samples-reviewers
 /functions/spanner/*                   @GoogleCloudPlatform/api-spanner-python @GoogleCloudPlatform/functions-framework-google @GoogleCloudPlatform/python-samples-reviewers @GoogleCloudPlatform/cloud-samples-reviewers
+/geminidataanalytics/**/*              @GoogleCloudPlatform/data-engineering-agent-team @GoogleCloudPlatform/python-samples-reviewers @GoogleCloudPlatform/cloud-samples-reviewers
 /healthcare/**/*                       @GoogleCloudPlatform/healthcare-life-sciences @GoogleCloudPlatform/python-samples-reviewers @GoogleCloudPlatform/cloud-samples-reviewers
 /retail/**/*                           @GoogleCloudPlatform/cloud-retail-team @GoogleCloudPlatform/python-samples-reviewers @GoogleCloudPlatform/cloud-samples-reviewers
 /billing/**/*                          @GoogleCloudPlatform/billing-samples-maintainers @GoogleCloudPlatform/python-samples-reviewers @GoogleCloudPlatform/cloud-samples-reviewers

geminidataanalytics/dataengineeringagent/requirements.txt

@@ -0,0 +1,3 @@
+a2a-sdk==1.0.3
+httpx==0.28.1
+google-auth==2.52.0