Upgrade to tycho 2.7.5

Currently the latest published Tycho 2.x is 2.7.5. It only works with Java 11 or later.

This is not entirely necessary but it is good to keep up with the updates in Tycho as well to avoid dragging behind too much.

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Ended up using Tycho 2.7.5 for this issue which is the latest 2.x release before 3.x.