Fix and circumvent new Rust 1.83 lints

[MarijnS95]

Rust 1.83 now detects when we unnecessarily specify lifetimes that can be omitted in impl blocks:

warning: the following explicit lifetimes could be elided: 'r
  --> ash/src/lib.rs:85:6
   |
85 | impl<'r, T> RawPtr<T> for Option<&'r T> {
   |      ^^                           ^^
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
help: elide the lifetimes
   |
85 - impl<'r, T> RawPtr<T> for Option<&'r T> {
85 + impl<T> RawPtr<T> for Option<&T> {
   |

Simple manual cases are solved but autogenerated code is omitted via allow(clippy::needless_lifetimes) because they are incredibly hard to track correctly; we might solve these individually in followup PRs. The main cause of these violations is structs with only a reference via their pNext pointer, but no known structextends and hence no push_next() in the builder impl block. In this case clippy suggests to replace the otherwise-unused forwarding of 'a in impl<'a> StructName<'a> to impl StructName<'_>.

Then there is one special case remaining in AllocationCallbacks which only holds an opaque p_user_data: *mut c_void pointer but we still assign a lifetime and PhantomData to it. We don't track/update the lifetime in the builder at all and might as well strip the lifetime away from this structure entirely.

Finally, clippy detects that our ash-examples crate doesn't have an MSRV and suggests to use C-string literals which are stable since Rust 1.77.