all: fix new lint warnings from bumping staticcheck

In prep for updating to new staticcheck required for Go 1.23.

Updates #12912

Change-Id: If77892a023b79c6fa798f936fc80428fd4ce0673
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

net/art/table_test.go

@@ -589,7 +589,7 @@ func TestInsertCompare(t *testing.T) {
 	}
 
 	if debugInsert {
-		t.Logf(fast.debugSummary())
+		t.Log(fast.debugSummary())
 	}
 
 	seenVals4 := map[int]bool{}