Update amundsendev/amundsen-search Docker tag to v4.2.0

This MR contains the following updates:

Package	Type	Update	Change
amundsendev/amundsen-search		minor	4.1.1 -> 4.2.0
amundsendev/amundsen-search	ironbank-docker	minor	4.1.1 -> 4.2.0
amundsendev/amundsen-search	stage	minor	4.1.1 -> 4.2.0

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