chore(deps): update flink docker tag to v1.19.0

This MR contains the following updates:

Package	Type	Update	Change
flink	ironbank-docker	minor	1.18.1-scala_2.12 -> 1.19.0-scala_2.12
flink	stage	minor	1.18.1-scala_2.12 -> 1.19.0-scala_2.12

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