[CALCITE-4188] Add hints from review #189

Job	Run time
CheckerFramework (JDK 11, oldest Guava)	9m 10s
CheckerFramework (JDK 11)	9m 10s
ErrorProne (JDK 11, latest Guava)	2m 18s
Linux (JDK 11, Avatica main)	3m 22s
Druid Tests	5m 51s
Linux (JDK 11, Pacific/Chatham Timezone)	2m 21s
Linux (JDK 21)	2m 19s
Linux (JDK 17)	2m 15s
Linux (JDK 23)	2m 25s
Linux (JDK 8, latest Guava, America/New_York Timezone)	2m 31s
Linux (JDK 8) Slow Tests	0s
Linux (JDK 8, oldest Guava, America/New_York Timezone)	2m 22s
macOS (JDK 21)	6m 23s
Windows (JDK 17)	4m 7s
Windows (JDK 21)	3m 48s
Windows (JDK 8)	4m 58s
	1h 3m 20s

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