[#13323] test(client): Add Ray Data Iceberg REST contract tests

[jiangxt2]

What changes were proposed in this pull request?

This pull request adds a Gravitino-owned Ray Data Iceberg REST integration test to the Python client test suite.

The change:

• adds pinned Ray 2.55.1, PyIceberg 0.12.0, and pandas 2.3.3 test dependencies;
• adds a dedicated rayIcebergIT Gradle task with an isolated Python environment;
• generates the ignored gravitino/version.ini file before running the client test;
• configures the Gravitino Iceberg REST auxiliary service with the dynamic catalog provider;
• uses Gravitino's memory Iceberg catalog and PyIceberg to create a namespace and pre-existing table fixture;
• verifies empty-table reads, Ray Data writes, subsequent reads, field order, row counts, and filtering;
• adds setup-failure cleanup for Gravitino configuration, metadata, and temporary data.

The implementation does not modify Java Iceberg REST code, Ray source code, or Ray Catalog.resolve() behavior.

Why are the changes needed?

Gravitino documents Ray Data access through the Iceberg REST endpoint and catalog_kwargs, but the Python client integration suite did not have a real end-to-end regression test for this contract.

The test protects the existing-table read/write path and validates the Gravitino auxiliary service lifecycle using the existing Lance Ray IT as the implementation baseline.

Fix: #13323

Does this PR introduce any user-facing change?

No end-user API or runtime behavior changes are introduced; contributor-facing Python integration-test tooling is added.

How was this patch tested?

Passed:

• git diff --check
• ruff check --no-cache clients/client-python/tests/integration/test_ray_iceberg.py
• ruff format --check --no-cache clients/client-python/tests/integration/test_ray_iceberg.py
• Gradle task graph for :clients:client-python:rayIcebergIT --dry-run
• ./gradlew :clients:client-python:rayIcebergIT --no-daemon --console=plain — passed; 1 test ran and completed successfully.

Before running the E2E, build or reuse the Gravitino distribution with ./gradlew compileDistribution -PskipWeb=true -x test.

This E2E is currently opt-in/manual and is not wired into the default CI workflow.

[github-actions]

Code Coverage Report

Overall Project	70.57% -0.25%	🟢
Files changed	50.4%	🔴

Module	Coverage
aliyun	19.74%	🔴
api	51.99%	🟢
authorization-common	85.96%	🟢
authorization-ranger	4.38% -1.22%	🔴
aws	53.54%	🟢
aws-bundle	0.0%	🔴
azure	32.1%	🔴
azure-bundle	0.0%	🔴
catalog-common	28.55%	🔴
catalog-fileset	82.28%	🟢
catalog-glue	71.52%	🟢
catalog-hive	83.08%	🟢
catalog-jdbc-common	45.72%	🟢
catalog-jdbc-doris	83.47%	🟢
catalog-jdbc-mysql	81.8%	🟢
catalog-jdbc-postgresql	83.89%	🟢
catalog-jdbc-starrocks	79.16%	🟢
catalog-kafka	75.21%	🟢
catalog-lakehouse-generic	63.27% +5.01%	🟢
catalog-lakehouse-hudi	79.1%	🟢
catalog-lakehouse-iceberg	85.98%	🟢
catalog-lakehouse-paimon	84.31%	🟢
catalog-model	77.99%	🟢
cli	44.62%	🟢
client-java	78.46%	🟢
common	58.2%	🟢
core	84.92% -0.11%	🟢
filesystem-hadoop3	76.48%	🟢
flink	18.07%	🔴
flink-common	53.95%	🟢
flink-runtime	0.0%	🔴
gcp	32.2%	🔴
hadoop-auth	68.0%	🟢
hadoop-common	17.84%	🔴
hive-metastore-common	54.41%	🟢
iceberg-aliyun-bundle	0.0%	🔴
iceberg-common	66.16%	🟢
iceberg-rest-server	77.1%	🟢
idp-basic	86.77%	🟢
integration-test-common	0.0%	🔴
jobs	59.96%	🟢
lance-common	36.14%	🔴
lance-rest-server	69.51%	🟢
lineage	59.39%	🟢
optimizer	83.33%	🟢
optimizer-api	42.56%	🟢
server	90.23% +0.04%	🟢
server-common	82.37%	🟢
spark	60.5%	🟢
tencent	81.78%	🟢
trino-connector	61.99%	🟢

Files

Module	File	Coverage
authorization-ranger	RangerAuthorizationHadoopSQLPlugin.java	0.0%	🔴
catalog-lakehouse-generic	LanceTableOperations.java	66.4%	🟢
core	TableMetaService.java	100.0%	🟢
	TableHookDispatcher.java	90.0%	🟢
	TableColumnMetaService.java	75.0%	🟢
	AuthorizationUtils.java	66.54%	🟢
server	MetadataObjectRoleOperations.java	100.0%	🟢