Resolves#15968. Since this feature never worked, and enabling it in the
`image` crate requires system dependencies, we've decided that it's best
to just remove it and let other plugin crates offer support for it as
needed.
## Migration Guide
AVIF images are no longer supported. They never really worked, and
require system dependencies (libdav1d) to work correctly, so, it's
better to simply offer this support via an unofficial plugin instead as
needed. The corresponding types have been removed from Bevy to account
for this.
# Objective
Bevy supports feature gates for each format it supports, but several
formats that it loads via the `image` crate do not have feature gates.
Additionally, the QOI format is supported by the `image` crate and
wasn't available at all. This fixes that.
## Solution
The following feature gates are added:
* `avif`
* `ff` (Farbfeld)
* `gif`
* `ico`
* `qoi`
* `tiff`
None of these formats are enabled by default, despite the fact that all
these formats appeared to be enabled by default before. Since
`default-features` was disabled for the `image` crate, it's likely that
using any of these formats would have errored by default before this
change, although this probably needs additional testing.
## Testing
The changes seemed minimal enough that a compile test would be
sufficient.
## Migration guide
Image formats that previously weren't feature-gated are now
feature-gated, meaning they will have to be enabled if you use them:
* `avif`
* `ff` (Farbfeld)
* `gif`
* `ico`
* `tiff`
Additionally, the `qoi` feature has been added to support loading QOI
format images.
Previously, these formats appeared in the enum by default, but weren't
actually enabled via the `image` crate, potentially resulting in weird
bugs. Now, you should be able to add these features to your projects to
support them properly.
