Update eclipse/rdf4j-workbench Docker tag to v5

This MR contains the following updates:

Package	Type	Update	Change
eclipse/rdf4j-workbench		major	4.3.12 -> 5.0.0
eclipse/rdf4j-workbench	ironbank-docker	major	4.3.12 -> 5.0.0
eclipse/rdf4j-workbench	stage	major	4.3.12 -> 5.0.0

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