Add libm feature to bevy_math (#11238)

# Objective

Different platforms use their own implementations of several
mathematical functions (especially transcendental functions like sin,
cos, tan, atan, and so on) to provide hardware-level optimization using
intrinsics. This is good for performance, but bad when you expect
consistent outputs across machines.

[`libm`](https://github.com/rust-lang/libm) is a widely used crate that
provides mathematical functions that don't use intrinsics like `std`
functions. This allows bit-for-bit deterministic math across hardware,
which is crucial for things like cross-platform deterministic physics
simulation.

Glam has the `libm` feature for using [`libm` for the
math](d2871a151b/src/f32/math.rs (L35))
in its own types. This would be nice to expose as a feature in
`bevy_math`.

## Solution

Add `libm` feature to `bevy_math`. We could name it something like
`enhanced-determinism`, but this wouldn't be accurate for the rest of
Bevy, so I think just `libm` is more fitting and explicit.

crates/bevy_math/Cargo.toml

@@ -18,6 +18,9 @@ serialize = ["dep:serde", "glam/serde"]
 approx = ["glam/approx"]
 # Enable interoperation of glam types with mint-compatible libraries
 mint = ["glam/mint"]
+# Enable libm mathematical functions for glam types to ensure consistent outputs
+# across platforms at the cost of losing hardware-level optimization using intrinsics
+libm = ["glam/libm"]
 # Enable assertions to check the validity of parameters passed to glam
 glam_assert = ["glam/glam-assert"]
 # Enable assertions in debug builds to check the validity of parameters passed to glam