Update dependency Azure.Identity to 1.15.0

Author: dependencyupdates[bot]

src/Directory.Packages.props

@@ -9,7 +9,7 @@
     <PackageVersion Include="AWSSDK.CloudWatch" Version="4.0.1.16" />
     <PackageVersion Include="AWSSDK.SecurityToken" Version="4.0.2" />
     <PackageVersion Include="AWSSDK.SQS" Version="4.0.1" />
-    <PackageVersion Include="Azure.Identity" Version="1.14.0" />
+    <PackageVersion Include="Azure.Identity" Version="1.15.0" />
     <PackageVersion Include="Azure.Messaging.ServiceBus" Version="7.20.1" />
     <PackageVersion Include="Azure.Monitor.Query" Version="1.6.0" />
     <PackageVersion Include="GitHubActionsTestLogger" Version="2.4.1" />