Remove aspect ratio warning when using theme(panel.widths, panel.heights)

[teunbrand]

This PR aims to fix #6701.

Essentially, it undoes 66e37cb in favour of documenting the behaviour.

[teunbrand]

TODO:

• Try to respect aspect ratios when provided

[teunbrand]

Reprex from issue, note the 1:1 aspect ratio is preserved.

devtools::load_all("~/packages/ggplot2/")

data.frame(cat = c("A", "B", "C"), value = c(25, 40, 60)) |>
  ggplot(aes(x = NA, y = value, fill = cat)) +
  geom_col(position = position_stack()) +
  coord_radial(theta = "y", expand = FALSE) +
  theme(panel.widths = unit(50, "mm"))

^{Created on 2025-10-21 with reprex v2.1.1}