internal/regtest: skip TestQuickFixEmptyFiles: it is too flaky

Updates golang/go#48773

Change-Id: Ic11f0a78c8ef13349fb521fe9a276dabeb574d4b
Reviewed-on: https://go-review.googlesource.com/c/tools/+/361157
Trust: Robert Findley <[email protected]>
Run-TryBot: Robert Findley <[email protected]>
gopls-CI: kokoro <[email protected]>
Reviewed-by: Bryan C. Mills <[email protected]>
TryBot-Result: Go Bot <[email protected]>

Author: findleyr

gopls/internal/regtest/diagnostics/diagnostics_test.go

@@ -967,6 +967,8 @@ const C = a.A
 // This is a copy of the scenario_default/quickfix_empty_files.txt test from
 // govim. Reproduces golang/go#39646.
 func TestQuickFixEmptyFiles(t *testing.T) {
+	t.Skip("too flaky: golang/go#48773")
+
 	testenv.NeedsGo1Point(t, 15)
 
 	const mod = `