[CALCITE-4339] Update Gradle: 6.6 -> 6.7
[CALCITE-4339] Update Gradle: 6.6 -> 6.7

jcamachor/calcite,jcamachor/calcite,jcamachor/calcite,looker-open-source/calcite,julianhyde/calcite,apache/calcite,julianhyde/calcite,apache/calcite,looker-open-source/calcite,julianhyde/calcite,julianhyde/calcite,apache/calcite,jcamachor/calcite,apache/calcite,jcamachor/calcite,jcamachor/calcite,julianhyde/calcite,looker-open-source/calcite,apache/calcite,looker-open-source/calcite,looker-open-source/calcite,looker-open-source/calcite,julianhyde/calcite,apache/calcite