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MINOR: Fix build double declaration (#36876)



### Rationale for this change
#36811 and #36854 both introduced a helper in their tests, but the result after merge was a collision causing it to be declared twice which made the Go build fail. By removing one of the duplicate declarations the build is fixed.

Authored-by: Matt Topol <zotthewizard@gmail.com>
Signed-off-by: Matt Topol <zotthewizard@gmail.com>