Properly setup rustup in dev container

Author: MonsieurNicolas

.devcontainer/Dockerfile

@@ -67,7 +67,6 @@ RUN apt-get -y install cpp-10 gcc-10 g++-10
 # clang
 RUN apt-get -y install clang-12 llvm-12
 # rust
-RUN ./install-rust.sh
 ENV PATH "/root/.cargo/bin:$PATH"
 
 # clang by default

.devcontainer/devcontainer.json

@@ -8,6 +8,7 @@
 			"APT_MIRROR": "${localEnv:APT_MIRROR}"
 		}
 	},
+	"onCreateCommand": "./install-rust.sh",
 	// The optional 'runArgs' property can be used to specify additional runtime arguments.
 	"runArgs": [
 		// Uncomment the line if you will use a ptrace-based debugger like C++, Go, and Rust.