Remove jitter workaround (#208)

* Remove a workaround for jitter in ggplot2 <3.3.4

* Remove test

tests/testthat/test-label.R

@@ -93,17 +93,4 @@ test_that("generate_labelled_layer() geenrates a layer for label with ggrepel.",
   l_jitter <- geom_point(aes(x, y, colour = type), d, position = position_jitter())
   l_label <- generate_labelled_layer(list(l_jitter), list(g_info), type2_quo, list(fill = "white"), Inf, "ggrepel_label")
   expect_equal(l_label$position$seed, l_jitter$position$seed)
-
-  # TODO: remove the following tests when gghighlight requires ggplot2 >= v3.3.4.
-  # when the seed is NULL, set it and share it. (c.f. tidyverse/ggplot2#2507, which is already fixed in v3.3.4)
-  l_jitter <- geom_point(aes(x, y, colour = type), d, position = "jitter")
-  if (is.null(l_jitter$position$seed)) {
-    l_label <- generate_labelled_layer(list(l_jitter), list(g_info), type2_quo, list(fill = "white"), Inf, "ggrepel_label")
-    expect_true(!is.null(l_jitter$position$seed))
-    expect_equal(l_label$position$seed, l_jitter$position$seed)
-
-    # Do not modify the original env
-    expect_true(is.null(ggplot2::PositionJitter$seed))
-  }
 })
-