Update resvg dependency of egui_extras (#3719)

Update `resvg` from v0.28 to v0.37. 
Remove related, unnecessary entries from `deny.toml`.

⚠ In example `images` ferris is scaled differently, but I guess that now
it scales in expected way (takes all available space; before this PR it
takes up to space that, was available at first render- it does not
upscale).

This PR is minimal adaptation to new `resvg` api and small related
simplification, however it should be considered to update loaders
(currently if svg image initially was small and was scaled up it will be
blurred, see https://github.com/emilk/egui/issues/3501). As svg image
now scales over render size, problem will be more often seen now.

(currently `SvgLoader` theoretically should rerender for different sizes
(but I guess it will result in memory leak in that case), but refreshing
is stopped earlier in `DefaultTextureLoader`).

I have initial version of loaders update, that will fix issue with svg
scaling (and also enable e.g. reloading image if file has been changed),
I will submit these changes in separate PR once this one is merged.

Closes <https://github.com/emilk/egui/issues/3652>.

crates/egui/src/load.rs

@@ -127,8 +127,6 @@ pub type Result<T, E = LoadError> = std::result::Result<T, E>;
 /// Used mostly for rendering SVG:s to a good size.
 ///
 /// All variants will preserve the original aspect ratio.
-///
-/// Similar to `usvg::FitTo`.
 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub enum SizeHint {
     /// Scale original size by some factor.