gopls/internal/regtest/bench: run kubernetes benchmarks with -short

Although kubernetes is a medium-large dashboard, allow it with -short as
it is a critical use-case for gopls, and we want to see its benchmarks
on perf.golang.org (which filters to -short benchmarks).

Change-Id: Ifc4cacfbd1fcde7aa50b0cbb74525fe71960c84f
Reviewed-on: https://go-review.googlesource.com/c/tools/+/487139
gopls-CI: kokoro <noreply+kokoro@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Alan Donovan <adonovan@google.com>

gopls/internal/regtest/bench/repo_test.go

@@ -40,6 +40,7 @@ var repos = map[string]*repo{
 		name:   "kubernetes",
 		url:    "https://github.com/kubernetes/kubernetes",
 		commit: "v1.24.0",
+		short:  true,
 		inDir:  flag.String("kubernetes_dir", "", "if set, reuse this directory as kubernetes@v1.24.0"),
 	},