Relaxing the Requirements for the Constant Time Versions of `erase_begin` and `erase_end`

Currently, the constant time versions of `erase_begin` and `erase_end` are only applied when `value_type` is a scalar type. However, this requirement is overly restrictive.

For example, in the case of `std::pair`, the current `circular_buffer` requires `O(n)` time to perform `erase_end`, which is actually unnecessary.

The `O(n)` version of erase seems to simply destruct elements. Therefore, would it be possible to relax the condition for the fast erase versions from `is_scalar` to `is_trivially_destructible`, allowing types like `std::pair` or other user-defined simple types to benefit from the faster `erase_begin` and `erase_end`?