playground/socket: eliminate an arbitrary timeout in TestLimiter
playground/socket: eliminate an arbitrary timeout in TestLimiter

Fixes golang/go#55238.

Change-Id: I17fe3865f7ec4d8889cdf71497b10a2ad0b41c11
Reviewed-on: https://go-review.googlesource.com/c/tools/+/451598
TryBot-Result: Gopher Robot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Run-TryBot: Bryan Mills <1c8aad60184261ccede67f5c63a0d2a3bf3c9ff4@google.com>
Auto-Submit: Bryan Mills <1c8aad60184261ccede67f5c63a0d2a3bf3c9ff4@google.com>
gopls-CI: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>
Reviewed-by: Robert Findley <9179eee875d1ee628c37fb47d7e749e855ffd21f@google.com>

golang/tools,golang/tools,golang/tools,golang/tools,golang/tools