chore: update rust toolchain

Signed-off-by: Patrick Roy <[email protected]>

Author: roypat

docker.env

@@ -2,4 +2,4 @@ IMAGE_NAME=rustvmm/dev
 REGISTRY=index.docker.io
 GIT_COMMIT=$(git rev-parse HEAD)
 GIT_BRANCH=$(git rev-parse --abbrev-ref HEAD)
-RUST_TOOLCHAIN="1.87.0"
+RUST_TOOLCHAIN="1.90.0"