net: increase timeout for TestDialerDualStackFDLeak
net: increase timeout for TestDialerDualStackFDLeak

This test has been getting occasional timeouts on the race builder.
The point of the test is whether a file descriptor leaks, not whether
the connection occurs in a certain amount of time. So use a very large
timeout. The connection is normally fast and the timeout doesn't matter.

Updates #13324

Change-Id: Ie1051c4a0be1fca4e63b1277101770be0cdae512
Reviewed-on: https://go-review.googlesource.com/82916
Run-TryBot: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>

codestation/go,josharian/go,akutz/go,CAFxX/go,cloudflare/go,akutz/go,golang/go,nawawi/go,Cofyc/go,codestation/go,cloudflare/go,Cofyc/go,nawawi/go,codestation/go,golang/go,Cofyc/go,nawawi/go,CAFxX/go,josharian/go,josharian/go,josharian/go,golang/go,cloudflare/go,nawawi/go,CAFxX/go,cloudflare/go,cloudflare/go,codestation/go,golang/go,akutz/go,golang/go,akutz/go,codestation/go,cloudflare/go,cloudflare/go,josharian/go,codestation/go,Cofyc/go,christopher-henderson/Go,CAFxX/go,codestation/go,Cofyc/go,Cofyc/go,CAFxX/go,golang/go,nawawi/go,cloudflare/go,nawawi/go,josharian/go,golang/go,josharian/go,akutz/go,CAFxX/go,nawawi/go,josharian/go,akutz/go,CAFxX/go,codestation/go,akutz/go,Cofyc/go,nawawi/go,akutz/go,CAFxX/go,Cofyc/go,golang/go