null unit legend key size failed

[Yunuuuu]

library(ggplot2)
library(patchwork)
p1 <- ggplot(mtcars) +
  geom_point(aes(mpg, disp)) +
  ggtitle("Plot 1")

p3 <- ggplot(mtcars) +
  geom_point(aes(hp, wt, colour = mpg)) +
  ggtitle("Plot 3")
p <- patchwork::wrap_plots(
  p1, p3 + scale_color_continuous(guide = guide_colorbar(
    theme = theme(legend.key.height = unit(1, "null"))
  )),
  ncol = 1L,
  guides = "collect"
)
print(p)
#> Error: Cannot create zero-length unit vector ("unit" subsetting)

^{Created on 2025-05-30 with reprex v2.1.0}
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[Yunuuuu]

Oh, I found the same issue in #6484