Replace deprecated --slow-spec-threshold Ginkgo flag with `--poll-p…

…rogress-after` (#6834)

* Replace deprecated '--slow-spec-threshold' Ginkgo flag with '--poll-progress-after'

Per [1], this instructs Ginkgo to automatically emit a progress report
whenever a node takes too long to complete.
The Progress Report includes information about which node is currently running
and the exact line of code that it is currently executing,
along with any relevant goroutines that were launched by the spec.

[1] https://onsi.github.io/ginkgo/#getting-visibility-into-long-running-specs

* Also set '--poll-progress-interval' flag so as to get progress reports periodically

Makefile

@@ -29,8 +29,8 @@ else
    TEST_EXEC_NODES := 4
 endif
 
-# Slow spec threshold for ginkgo tests. After this time (in second), ginkgo marks test as slow
-SLOW_SPEC_THRESHOLD := 120s
+# After this time, Ginkgo will emit progress reports, so we can get visibility into long-running tests.
+POLL_PROGRESS_INTERVAL := 120s
 
 # Env variable GINKGO_TEST_ARGS is used to get control over enabling ginkgo test flags against each test target run.
 # For example:
@@ -53,7 +53,7 @@ else
    PODMAN_EXEC_NODES := 1
 endif
 
-GINKGO_FLAGS_ALL = $(GINKGO_TEST_ARGS) --randomize-all --slow-spec-threshold=$(SLOW_SPEC_THRESHOLD) -timeout $(TIMEOUT) --no-color
+GINKGO_FLAGS_ALL = $(GINKGO_TEST_ARGS) --randomize-all --poll-progress-after=$(POLL_PROGRESS_INTERVAL) --poll-progress-interval=$(POLL_PROGRESS_INTERVAL) -timeout $(TIMEOUT) --no-color
 
 # Flags to run one test per core.
 GINKGO_FLAGS_AUTO = $(GINKGO_FLAGS_ALL) -p