Add script to run CI locally

* This is the same CI that runs remotely automatically with PRs. This is a
  posix shell script.
* Remove a bit of cruft as well

.gitignore

@@ -15,3 +15,4 @@ crates/oq3_syntax/src/ast/generated/_new_tokens.rs
 .env/
 .envs/
 .ackrc
+save/

local_CI.sh

@@ -0,0 +1,6 @@
+#!/bin/env sh
+
+# Run locally the same checks that are done remotely in CI
+# Works on linux, and maybe Mac OS.
+
+cargo fmt --all -- --check && cargo build --verbose && cargo clippy -- -D warnings && cargo test --verbose -- --skip sourcegen_ast --skip sourcegen_ast_nodes

rust-toolchain.toml

@@ -3,8 +3,6 @@
 
 # Copyright contributors to the openqasm-parser project
 
-# FIXME: Our min required version is > than 1.64.0
-
 channel = "1.70.0"
 components = [
   "cargo",