test: evict finished executions from the in-memory cache more aggressively

ExecutionsService's ExecutionObject cache only calls shutdown() (which
tears down that execution's dedicated Executors.newFixedThreadPool) on
eviction, gated by app.executions.cache.max-size (default 1000) and
app.executions.cache.final-ttl-ms (default 30 minutes). The Spring test
context - and its singleton ExecutionsService - is reused across the
whole suite, and a full run finishes in well under 30 minutes with far
fewer than 1000 executions, so none of that cleanup ever fires: every
execution's thread pool stays alive simultaneously for the rest of the
run. That's a plausible contributor to the loop-container tests
occasionally missing their polling deadline under full-suite load
(they pass reliably in isolation, where far fewer executions
accumulate). Lowering both knobs for tests only keeps the live
thread-pool count small throughout a run; eviction only ever targets
already-finished executions (see evictIfNeeded/evictFinalStateByTtl),
so this cannot disrupt an in-flight test.

src/test/resources/test.properties

@@ -20,3 +20,15 @@ app.assistant.provider-retry-max-delay-ms=2
 
 app.import.path=src/test/resources/workflow-editor-init
 app.import.enabled=true
+
+# The Spring test context (and its singleton ExecutionsService) is reused across the whole
+# suite. Each execution gets its own dedicated Executors.newFixedThreadPool that only gets
+# shut down on cache eviction (see ExecutionsService.evictIfNeeded/evictFinalStateByTtl) -
+# with the production default of 1000 and a 30-minute TTL, a full test run (hundreds of
+# executions, none older than 30 minutes) never evicts anything, so hundreds of finished-but-
+# not-shut-down thread pools stay alive simultaneously. That OS-level thread contention is the
+# most likely cause of the loop-container tests occasionally missing their polling deadline
+# under full-suite load (they pass reliably in isolation). Evicting aggressively in tests keeps
+# the live thread-pool count small throughout the run.
+app.executions.cache.max-size=50
+app.executions.cache.final-ttl-ms=2000