Use workspace lints to control unexpected_cfgs. (#682)

By using `workspace.lints`, we can configure lints once for
everything (and then inherit it into the various crates).

The lint configuration for `unexpected_cfgs` works in 1.80+
and warns otherwise.

Co-authored-by: Thierry Berger <contact@thierryberger.com>

Cargo.toml

@@ -3,6 +3,14 @@ members = ["crates/rapier2d", "crates/rapier2d-f64", "crates/rapier_testbed2d",
     "crates/rapier3d", "crates/rapier3d-f64", "crates/rapier_testbed3d", "crates/rapier_testbed3d-f64", "examples3d", "examples3d-f64", "benchmarks3d", "crates/rapier3d-urdf", "crates/rapier3d-stl"]
 resolver = "2"
 
+[workspace.lints]
+rust.unexpected_cfgs = { level = "warn", check-cfg = [
+    'cfg(feature, values("dim2", "dim3", "f32", "f64"))',
+    # The `other-backends` feature isn't in the tested3d-f64
+    # but easier to just ignore it here.
+    'cfg(feature, values("other-backends"))',
+] }
+
 [patch.crates-io]
 #wrapped2d = { git = "https://github.com/Bastacyclop/rust_box2d.git" }
 #xurdf = { path = "../xurdf/xurdf" }