dependency confict with bevvy 0.8

[matthis-k]

bevy 0.8 and heron 3.1.0 have a dependency conflict:

error: failed to select a version for `web-sys`.
    ... required by package `wgpu v0.12.0`
    ... which satisfies dependency `wgpu = "^0.12.0"` of package `bevy_render v0.7.0`
    ... which satisfies dependency `bevy_render = "^0.7.0"` of package `bevy_core_pipeline v0.7.0`
    ... which satisfies dependency `bevy_core_pipeline = "^0.7.0"` of package `bevy_pbr v0.7.0`
    ... which satisfies dependency `bevy_pbr = "^0.7.0"` of package `bevy_internal v0.7.0`
    ... which satisfies dependency `bevy_internal = "^0.7.0"` of package `bevy v0.7.0`
    ... which satisfies dependency `bevy = "^0.7.0"` of package `heron v3.1.0`
    ... which satisfies dependency `heron = "^3.1.0"` of package `asdf v0.1.0 (...)`
versions that meet the requirements `^0.3.53` are: 0.3.59, 0.3.58, 0.3.57, 0.3.56, 0.3.55, 0.3.54, 0.3.53

the package `wgpu` depends on `web-sys`, with features: `GpuBufferUsage` but `web-sys` does not have these features.

all possible versions conflict with previously selected packages.

  previously selected package `web-sys v0.3.58`
    ... which satisfies dependency `web-sys = "^0.3.53"` of package `wgpu v0.12.0`
    ... which satisfies dependency `wgpu = "^0.12.0"` of package `bevy_render v0.7.0`
    ... which satisfies dependency `bevy_render = "^0.7.0"` of package `bevy_core_pipeline v0.7.0`
    ... which satisfies dependency `bevy_core_pipeline = "^0.7.0"` of package `bevy_pbr v0.7.0`
    ... which satisfies dependency `bevy_pbr = "^0.7.0"` of package `bevy_internal v0.7.0`
    ... which satisfies dependency `bevy_internal = "^0.7.0"` of package `bevy v0.7.0`
    ... which satisfies dependency `bevy = "^0.7.0"` of package `heron v3.1.0`
    ... which satisfies dependency `heron = "^3.1.0"` of package `asdf v0.1.0 (...)`

failed to select a version for `web-sys` which could resolve this conflict

[jcornaz]

First of all, heron 3.1.0 requires bevy 0.7. It is not compatible with bevy 0.8. (See the compatibility table)

That being said, this problem is actually caused by web-sys not complying to semver: They removed the cargo feature GpuBufferUsage in the patch release 0.3.58.