chore: bump MSRV to 1.70, add rust-toolchain (#2580)

Piotr Osiewicz created 

This time I've added a `components` section to rust-toolchain.toml file
to explicitly require a rustfmt component. Fingers crossed.

Change summary

Dockerfile          | 2 +-
rust-toolchain.toml | 3 +++
2 files changed, 4 insertions(+), 1 deletion(-)

Detailed changes

Dockerfile 🔗 

@@ -1,6 +1,6 @@
 # syntax = docker/dockerfile:1.2
 
-FROM rust:1.65-bullseye as builder
+FROM rust:1.70-bullseye as builder
 WORKDIR app
 COPY . .