perf: change RawVec grow_one from #[inline(never)] to #[inline]

I noticed that this was not inlined when trying to `push` and probably the reason why the compiler lose the information about the capacity (fixes #82801)

BTW The original PR that added it (#91352) wrote:
> [...] I tried lots of minor variations on this, e.g. different inlining
attributes. This was the best one I could find. [...]

I never contributed to Rust so I did not know how to test that it actually fixes the problem, but I'm fairly certain it is.

Consider the very basic example (Godbolt rustc 1.90.0 `-C opt-level=3 -C target-feature=+avx2 -C codegen-units=1`) 
```rust
#[no_mangle]
fn extend_offsets(offsets: &[usize]) -> Vec::<usize> {
    let mut intermediate = Vec::<usize>::with_capacity(offsets.len());

    for &offset in offsets {
        intermediate.push(offset)
    }

    intermediate
}
```

it does not inline `grow_one` which make it not use SIMD.

If however we are using [`push_within_capacity`](#100486):

```rust
#![feature(vec_push_within_capacity)]

#[no_mangle]
fn extend_offsets(offsets: &[usize]) -> Vec::<usize> {
    let mut intermediate = Vec::<usize>::with_capacity(offsets.len());

    for &offset in offsets {
        intermediate.push_within_capacity(offset).unwrap()
    }

    intermediate
}
```

it will use SIMD

Author: rluvaton

library/alloc/src/raw_vec/mod.rs

@@ -334,7 +334,7 @@ impl<T, A: Allocator> RawVec<T, A> {
     /// A specialized version of `self.reserve(len, 1)` which requires the
     /// caller to ensure `len == self.capacity()`.
     #[cfg(not(no_global_oom_handling))]
-    #[inline(never)]
+    #[inline]
     #[track_caller]
     pub(crate) fn grow_one(&mut self) {
         self.inner.grow_one(T::LAYOUT)