Bump Azure.Storage.Blobs

Bumps the service group in /src/FeatureFlags.Service with 1 update: [Azure.Storage.Blobs](https://github.com/Azure/azure-sdk-for-net).


Updates `Azure.Storage.Blobs` from 12.20.0 to 12.21.0
- [Release notes](https://github.com/Azure/azure-sdk-for-net/releases)
- [Commits](Azure/azure-sdk-for-net@Azure.Storage.Blobs_12.20.0...Azure.Storage.Blobs_12.21.0)

---
updated-dependencies:
- dependency-name: Azure.Storage.Blobs
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: service
...

Signed-off-by: dependabot[bot] <[email protected]>

src/FeatureFlags.Service/FeatureFlags.Service.csproj

@@ -11,7 +11,7 @@
     <PackageReference Include="Azure.Extensions.AspNetCore.Configuration.Secrets" Version="1.3.1" />
     <PackageReference Include="Azure.Identity" Version="1.12.0" />
     <PackageReference Include="Azure.Security.KeyVault.Secrets" Version="4.6.0" />
-    <PackageReference Include="Azure.Storage.Blobs" Version="12.20.0" />
+    <PackageReference Include="Azure.Storage.Blobs" Version="12.21.0" />
     <PackageReference Include="Microsoft.ApplicationInsights.AspNetCore" Version="2.22.0" />
     <PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="8.0.3" />
     <PackageReference Include="Swashbuckle.AspNetCore" Version="6.6.2" />