To maximise the space given to the data in a ggplot graph I want to stack the y-axis title (rotated horizontally for accessibility purposes) and the legend. This has been possible until now using legend.position. For example:

ggplot(iris, aes(Sepal.Length, Petal.Width, shape = Species, colour = Species)) +
  geom_point() +
  theme(axis.title.y = element_text(angle = 0, vjust = 0.9),
        legend.position = c(-0.15, 0.2))

Produces:
ggplot graph with legend positioned directly below the y-axis title

But now I’ve started using ggplot 3.5.0 I’m getting the message “Warning: A numeric legend.position argument in theme() was deprecated in ggplot2 3.5.0.”

So, I’ve been trying to produce a non-deprecated alternative to my code, using the latest official guidance on ggplot legends, but have not succeeded. For example:

ggplot(iris, aes(Sepal.Length, Petal.Width, shape = Species, colour = Species)) +
  geom_point() +
  theme(axis.title.y = element_text(angle = 0, vjust = 0.9),
        legend.position = "left", 
        legend.justification.left = "bottom")

Produces a graph where the legend is positioned below and to the left of the y-axis title, rather than directly below:
ggplot graph with legend positioned below and to the left of the y-axis title, rather than directly below it