os: skip TestExecutableDeleted on aix
os: skip TestExecutableDeleted on aix

aix does not support reading deleted executable name.

Change-Id: I955ed2c22bd0693440e2c889a4d3132d0a375c48
Reviewed-on: https://go-review.googlesource.com/c/go/+/312392
Run-TryBot: Tobias Klauser <0a68dd4915066ec5d3f81f75a828fee53dcc8822@gmail.com>
TryBot-Result: Go Bot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Tobias Klauser <0a68dd4915066ec5d3f81f75a828fee53dcc8822@gmail.com>
Reviewed-by: Than McIntosh <4b2922593166fc595a9b1a408f34f5d3817fe9d2@google.com>

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