gopls/internal/regtest/workspace: temporarily skip TestWatchReplaceTargets

This test has a high failure rate on the builders, and the failures
appear to be mostly platform-independent. This change skips the test
until the failures can be diagnosed and fixed.

For golang/go#50748

Change-Id: Iadfda7345f3dcbafa61338469aa6dc45e1d85a49
Reviewed-on: https://go-review.googlesource.com/c/tools/+/380215
Trust: Bryan Mills <bcmills@google.com>
Run-TryBot: Bryan Mills <bcmills@google.com>
Reviewed-by: Robert Findley <rfindley@google.com>
gopls-CI: kokoro <noreply+kokoro@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

Author: Bryan C. Mills

gopls/internal/regtest/workspace/workspace_test.go

@@ -194,6 +194,8 @@ func TestClearAnalysisDiagnostics(t *testing.T) {
 // This test checks that gopls updates the set of files it watches when a
 // replace target is added to the go.mod.
 func TestWatchReplaceTargets(t *testing.T) {
+	t.Skipf("skipping known-flaky test: see https://go.dev/issue/50748")
+
 	WithOptions(
 		ProxyFiles(workspaceProxy),
 		WorkspaceFolders("pkg"),