Add vcpkg to our release process

[claremacrae]

We’ll need to create a PR to update the vcpkg port, like we already do for Conan.

The original PR for adding vcpkg support is:
#18338 · microsoft/vcpkg · GitHub

The current content of our port is:
vcpkg/ports/approval-tests-cpp at master

Note that we won’t need to accumulate data for successive releases in the two port files - we will overwrite it, and then run some script to update some indexes.

[claremacrae]

This - and the scripts it uses - will be worth investigating:
https://github.com/Azure/azure-sdk-for-cpp/blob/main/eng/pipelines/templates/steps/vcpkg-publish.yml

[isidore]

believe this is done with python scripts now