Bug: regex [@-+] means "from @ to +", so "." and "\" was also colorized.
Bug is fixed in make.tmbundle, test case is added to vscode.
Update make grammar
1. @, - and + in the beginning of recipes are colored.
2. Shell in recipes is not colored by shellscript extension anymore:
improper colorizing of Makefile variables, low suitability.
1. Handling the '!=' variable assignment operator.
2. Handling the "#" (hashtag) in the quotes inside the recipe.
3. Restore the recipe handling.
Issue: #60030, #61475