Remove cbegin and cend calls which do not exist in std::span or gsl::span

[fdwr]

Description: Remove calls to cbegin and cend introduced in #10193 which are removed methods (see #1 #2), not present on std::span or gsl::span.

Motivation and Context

• Why is this change required? What problem does it solve? It breaks the WindowsAI build, conflicting because we use GSL's span, not GSL lite (which has the stale cbegin/cend). Plus, the iterators are already const anyway, given the function parameter is gsl::span<const int64_t>.
• If it fixes an open issue, please link to the issue here. NA

[snnn]

It seems that you are using a different gsl version than us. We should make it consistent.

[yuslepukhin]

I have not objection to this PR. The only thing, the number of places seems awfully small. I use cbegin() and cend() left and right. We should add it to the Coding Guidelines?

[fdwr]

The only thing, the number of places seems awfully small. I use cbegin() and cend() left and right.

@yuslepukhin: Yeah, you use it often, but for vector and string and such. For span, those were the only two places I encountered it.

[fdwr]

@snnn I see orttraining-amd-gpu-ci-pipeline failing, but my change is orthogonal to that (whatever the cause). So I'll submit given @yuslepukhin said he has no objections. As for how you want to update coding guidelines, I'll leave that to you 😊. Thanks.