Fix some warnings

[snnn]

Description:

Fix some warnings. For example:

member function but is not marked 'override' [-Werror,-Winconsistent-missing-override]
  virtual Status BeamSearch__Compute(const contrib::transformers::BeamSearch* p, OpKernelContext* ctx) { return p->contrib::transformers::BeamSearch::Compute(ctx); }

Motivation and Context

• Why is this change required? What problem does it solve?
• If it fixes an open issue, please link to the issue here.