Bump Azure.Security.KeyVault.Keys from 4.7.0 to 4.8.0#275

dependabot[bot] wants to merge 1 commit intomainAzure/notation-azure-kv:mainfrom

dependabot/nuget/Notation.Plugin.AzureKeyVault/Azure.Security.KeyVault.Keys-4.8.0Azure/notation-azure-kv:dependabot/nuget/Notation.Plugin.AzureKeyVault/Azure.Security.KeyVault.Keys-4.8.0Copy head branch name to clipboard