Clean up spelling unnecisary to unnecessary.

Author: PrototypeNM1

_posts/2021-07-16-release-0.9-future.md

@@ -20,7 +20,7 @@ See [gfx-rs changelog](https://github.com/gfx-rs/gfx/blob/master/CHANGELOG.md#ha
 
 `wgpu` validation has continued to improve. Many validation holes were plugged with the last release. Through the combined work in `wgpu` and `naga`, validation holes have been sured up, and new features have been implemented. One such feature is getting the array length of runtime-sized arrays, which is now properly implemented on metal.
 
-`wgpu` performance is still a vital target for us, so we have done work on improving the overhead of resource tracking. We've reduced unnecisary overhead through only doing stateful tracking for resources that have complex states. These changes were made from benchmarks of Gecko's WebGPU implemention which showed that tracking was a bottleneck. You can read more about it [#1413](https://github.com/gfx-rs/wgpu/issues/1413).
+`wgpu` performance is still a vital target for us, so we have done work on improving the overhead of resource tracking. We've reduced unnecessary overhead through only doing stateful tracking for resources that have complex states. These changes were made from benchmarks of Gecko's WebGPU implemention which showed that tracking was a bottleneck. You can read more about it [#1413](https://github.com/gfx-rs/wgpu/issues/1413).
 
 ## wgpu Family Reunion, Relicense, and the Future