[R-plotly] Hovertemplate fails in violin plot

I attempt to use the hovertemplate argument to format the hover text, but it cannot properly display.
However the argument works for type = "scatter". Similar issue was found in #1636 with box plot.

df <- tibble(x = sample(letters[1:3], 100, replace = T), y = rnorm(100))
df %>% plot_ly(
  x = ~x,
  y = ~y,
  split = ~x,
  type = 'violin',
  box = list(
    visible = TRUE
  ),
  hovertemplate = "%{y}", # not work
  hoveron = "kde",
  jitter = 1,
  alpha = 0.5,
  spanmode = "hard"
  )
)

Using text argument + hoverinfo will let the hover disappear completely

df %>% plot_ly(
  x = ~x,
  y = ~y,
  split = ~x,
  text = ~y, # using text argument
  type = 'violin',
  box = list(
    visible = TRUE
  ),
  hoverinfo = "text", # with hoverinfo
  hoveron = "kde",
  jitter = 1,
  alpha = 0.5,
  spanmode = "hard"
  )
)

Using hoverinfo = "y" comes along with kde

df %>% plot_ly(
  x = ~x,
  y = ~y,
  split = ~x,
  type = 'violin',
  box = list(
    visible = TRUE
  ),
  hoverinfo = "y",
  hoveron = "kde",
  jitter = 1,
  alpha = 0.5,
  spanmode = "hard"
  )

However, hoverinfo = "x" works properly,

df %>% plot_ly(
  x = ~x,
  y = ~y,
  split = ~x,
  type = 'violin',
  box = list(
    visible = TRUE
  ),
  hoverinfo = "x",
  hoveron = "kde",
  jitter = 1,
  alpha = 0.5,
  spanmode = "hard"
  )

R version = 4.0.5, R-plotly version = 4.9.3

提供された R のバイオリンプロットの例を再現し、その hover 動作を、動作している散布図のケースおよび関連するボックスプロットの issue #1636 と比較します。R の例から関連する plotly.R のエントリポイントまでバイオリンの hover 処理を追跡します。hovertemplate と hoverinfo が要求された y テキストを表示し、KDE の hover 情報を失わない状態になれば完了です。