[Key Vault] Update tsp-location commit pointers

[mccoyp]

Description

Now that 7.6 specs are in main, update pointers to the new location to enable releases.

All SDK Contribution checklist:

• The pull request does not introduce [breaking changes]
• CHANGELOG is updated for new features, bug fixes or other significant changes.
• I have read the contribution guidelines.

General Guidelines and Best Practices

• Title of the pull request is clear and informative.
• There are a small number of commits, each of which have an informative message. This means that previously merged commits do not appear in the history of the PR. For more information on cleaning up the commits in your PR, see this page.

Testing Guidelines

• Pull request includes test coverage for the included changes.

[Copilot]

Pull Request Overview

This PR updates the TypeSpec location commit pointers to the latest spec version now in main, enabling new releases for all Key Vault packages.

• Updated the commit SHA in each tsp-location.yaml to bc16bd3359c80260f1d1d523679fbe6806ce0813.
• Ensures all Key Vault subpackages point to the same new spec version.

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
sdk/keyvault/azure-keyvault-secrets/tsp-location.yaml	Bumped commit SHA to new main spec version
sdk/keyvault/azure-keyvault-keys/tsp-location.yaml	Bumped commit SHA to new main spec version
sdk/keyvault/azure-keyvault-certificates/tsp-location.yaml	Bumped commit SHA to new main spec version
sdk/keyvault/azure-keyvault-administration/tsp-location.yaml	Bumped commit SHA to new main spec version

[mccoyp]

/check-enforcer override