* test: add e2e for non-overlapping placements
Followup to #10446
Fails (as expected) against 1.3.x at the wait for blocked eval (because
the allocs are allowed to overlap).
Passes against 1.4.0-beta.1 (as expected).
* Update e2e/overlap/overlap_test.go
Co-authored-by: James Rasell <jrasell@users.noreply.github.com>