[CALCITE-6028] SqlToRelConverter#substituteSubQuery gives NullPointer… #33

Job	Run time
Error Prone (JDK 11), latest Guava	3m 45s
CheckerFramework (JDK 11)	9m 8s
Linux (JDK 11), Avatica main	11m 32s
CheckerFramework (JDK 11), oldest Guava	15m 53s
Druid Tests	6m 54s
Linux (JDK 11), Pacific/Chatham Timezone	9m 28s
Linux (JDK 17)	9m 6s
Linux (JDK 19)	12m 38s
Linux (JDK 8), latest Guava, America/New_York Timezone	11m 46s
Linux (JDK 8), oldest Guava, America/New_York Timezone	9m 20s
Linux (JDK 8) Slow Tests	0s
macOS (JDK 19)	21m 3s
Windows (JDK 17)	18m 9s
Windows (JDK 8)	21m 44s
	2h 40m 26s

Provide feedback