The removeDups template function converts a slice into a map and
back into a slice in order to leverage the map keys to remove
duplicates. However, since the iteration order over a map is not
specified it would be possible to get different orders for multiple runs
of `make api`. While this would not have an impact on any functionality,
it is causing sporadic failures for the new make-gen-deltas CI job.
See: https://go.dev/ref/spec#For_statements
Ref: d57603022a