Use workspace config in packages

- Apply lint config to entire workspace

- Inherit workspace config for fish-printf

- Allow stdlib printing in fish-printf tests

The current problem which is addressed by this is that warnings about C-String
literals are generated by clippy for code in fish-printf. These literals are not
available with the current MSRV 1.70, but previously the MSRV setting was not
inherited by fish-printf, causing the warning to appear.

printf/Cargo.toml

@@ -1,6 +1,7 @@
 [package]
 name = "fish-printf"
-edition = "2021"
+edition.workspace = true
+rust-version.workspace = true
 version = "0.2.1"
 repository = "https://github.com/fish-shell/fish-shell"
 description = "printf implementation, based on musl"
@@ -9,3 +10,6 @@ license = "MIT"
 [dependencies]
 libc = "0.2.155"
 widestring = { version = "1.0.2", optional = true }
+
+[lints]
+workspace = true