Use endpoint for system Nexus detection #5601

Job	Run time
check-protos	9m 46s
test-latest-deps	4m 6s
cloud-test	2m 10s
build-lint-test (3.10, macos-arm)	6m 26s
build-lint-test (3.10, windows-latest)	6m 56s
build-lint-test (3.14, ubuntu-latest)	3m 12s
build-lint-test (3.14, ubuntu-arm)	5m 56s
build-lint-test (3.10, ubuntu-arm)	5m 40s
features-tests / test	8m 46s
build-lint-test (3.10, ubuntu-latest)	4m 2s
build-lint-test (3.14, windows-latest)	8m 1s
build-lint-test (3.14, macos-arm)	7m 30s
	1h 12m 31s

Provide feedback