net/http/pprof: skip TestDeltaProfile on openbsd/arm
net/http/pprof: skip TestDeltaProfile on openbsd/arm

It is observed to be flaky on the only openbsd/arm builder.
Skipping on that platform until someone can investigate.

For #50218

Change-Id: Id3a6dc12b93b3cec67870d8d81bd608c4589c952
Reviewed-on: https://go-review.googlesource.com/c/go/+/372794
Trust: Bryan Mills <1c8aad60184261ccede67f5c63a0d2a3bf3c9ff4@google.com>
Run-TryBot: Bryan Mills <1c8aad60184261ccede67f5c63a0d2a3bf3c9ff4@google.com>
Reviewed-by: Hyang-Ah Hana Kim <d7e82c3c07f92613bcbf9a1e88f6b96c13caa3b0@gmail.com>
TryBot-Result: Gopher Robot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>

cloudflare/go,golang/go,nawawi/go,nawawi/go,cloudflare/go,golang/go,cloudflare/go,cloudflare/go,CAFxX/go,golang/go,golang/go,golang/go,CAFxX/go,cloudflare/go,nawawi/go,nawawi/go,nawawi/go,nawawi/go,cloudflare/go,CAFxX/go,nawawi/go,cloudflare/go,golang/go,CAFxX/go,golang/go,nawawi/go,cloudflare/go,CAFxX/go,golang/go,CAFxX/go,CAFxX/go,CAFxX/go