chore: bump MSRV to 1.70 (#2573)

Add rust-toolchain.toml

Release Notes:

- N/A

.github/workflows/ci.yml

@@ -26,6 +26,7 @@ jobs:
       - name: Install Rust
         run: |
           rustup set profile minimal
+          rustup component add rustfmt
           rustup update stable
 
       - name: Checkout repo

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 . .
 

rust-toolchain.toml

@@ -0,0 +1,2 @@
+[toolchain]
+channel = "1.70"