ci: guard empty matrix categories in integration test workflow

[musa-asad]

Summary

A filtered workflow_dispatch run of the integration test workflow (one that
sets a test_dir_filter or test_os_filter input) reduces every non-matching
test category to [] via apply_filters. Twelve inline matrix-consumer jobs in
.github/workflows/test-artifacts.yml expand

arrays: ${{ fromJson(needs.GenerateTestMatrix.outputs.<cat>_matrix) }}

with no emptiness guard. When the consumed output is [], fromJson('[]') makes
GitHub Actions reject the matrix with "Matrix vector 'arrays' does not contain
any values". The affected jobs are never created and the whole run is marked
failure, even though GenerateTestMatrix itself succeeded. Unfiltered (cron/bot)
runs keep every category populated, so the defect is latent until a filtered
dispatch hits it.

Changes

Added a job-level guard

if: ${{ needs.GenerateTestMatrix.outputs.<cat>_matrix != '[]' }}

to each of the 12 inline consumer jobs in .github/workflows/test-artifacts.yml,
using the matching category output per job:

Job	Category output
EC2NvidiaGPUIntegrationTest	ec2_gpu_matrix
EC2WinIntegrationTest	ec2_windows_matrix
EC2DarwinIntegrationTest	ec2_mac_matrix
ECSEC2IntegrationTest	ecs_ec2_launch_daemon_matrix
ECSFargateIntegrationTest	ecs_fargate_matrix
EKSIntegrationTest	eks_daemon_matrix
EKSPrometheusIntegrationTest	eks_deployment_matrix
PerformanceTrackingTest	ec2_performance_matrix
EC2WinPerformanceTest	ec2_windows_performance_matrix
StressTrackingTest	ec2_stress_matrix
EC2WinStressTrackingTest	ec2_windows_stress_matrix
GPUEndToEndTest	eks_addon_matrix

This mirrors the existing ec2_linux_matrix_page_count > N guards that already
protect the paginated EC2Linux jobs. When a category is empty the consumer job is
cleanly skipped instead of failing matrix expansion. Unfiltered runs are
unaffected. No Go code changes.

Test Output

Guard count is exactly 12 (one per inline consumer job):

$ grep -c "!= '\[\]'" .github/workflows/test-artifacts.yml
12

The workflow still parses as valid YAML:

$ python3 -c "import yaml; yaml.safe_load(open('.github/workflows/test-artifacts.yml')); print('YAML OK')"
YAML OK

The diff adds only the 12 guard lines and nothing else (excerpt):

   EC2NvidiaGPUIntegrationTest:
     needs: [ StartLocalStack, GenerateTestMatrix, OutputEnvVariables ]
+    if: ${{ needs.GenerateTestMatrix.outputs.ec2_gpu_matrix != '[]' }}
     name: ${{ matrix.arrays.wip && '[WIP] ' || '' }}${{matrix.arrays.testName}}
...
   ECSEC2IntegrationTest:
     name: ${{ matrix.arrays.wip && '[WIP] ' || '' }}${{matrix.arrays.testName}}
     runs-on: ubuntu-latest
     needs: [ GenerateTestMatrix, OutputEnvVariables ]
+    if: ${{ needs.GenerateTestMatrix.outputs.ecs_ec2_launch_daemon_matrix != '[]' }}
...
   GPUEndToEndTest:
     name:  ${{matrix.arrays.testName}}
     needs: [ GenerateTestMatrix, OutputEnvVariables ]
+    if: ${{ needs.GenerateTestMatrix.outputs.eks_addon_matrix != '[]' }}

CI Fix: Node.js 24 action runtime migration

GitHub Actions force-migrated several pinned actions off the deprecated Node.js 20
runtime. The deprecated Node.js 20 action SHAs pinned across .github/workflows/
were bumped to the latest Node.js 24-compatible releases to keep CI green.

Action	New tag	New SHA
actions/checkout	v7.0.0	9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0
actions/setup-go	v6.4.0	4a3601121dd01d1626a1e23e37211e3254c1c06c
aws-actions/configure-aws-credentials	v6.2.0	e7f100cf4c008499ea8adda475de1042d6975c7b
hashicorp/setup-terraform	v4.0.1	dfe3c3f87815947d99a8997f908cb6525fc44e9e
nick-fields/retry	v4.0.0	ad984534de44a9489a53aefd81eb77f87c70dc60
docker/build-push-action	v7.2.0	f9f3042f7e2789586610d6e8b85c8f03e5195baf
docker/setup-buildx-action	v4.1.0	d7f5e7f509e45cec5c76c4d5afdd7de93d0b3df5
docker/setup-qemu-action	v4.1.0	06116385d9baf250c9f4dcb4858b16962ea869c3

All actions now run on the node24 runtime.