Bump AWSSDK.SecurityToken in /src in the awssdk group across 1 directory

Bumps the awssdk group with 1 update in the /src directory: [AWSSDK.SecurityToken](https://github.com/aws/aws-sdk-net).


Updates `AWSSDK.SecurityToken` from 3.7.401.78 to 4.0.0
- [Release notes](https://github.com/aws/aws-sdk-net/releases)
- [Changelog](https://github.com/aws/aws-sdk-net/blob/main/SDK.CHANGELOG.MD)
- [Commits](https://github.com/aws/aws-sdk-net/commits/4.0.0.0)

---
updated-dependencies:
- dependency-name: AWSSDK.SecurityToken
  dependency-version: 4.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: awssdk
...

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

Author: dependabot[bot]

src/Directory.Packages.props

@@ -6,7 +6,7 @@
   <ItemGroup Label="Versions for direct package references">
     <PackageVersion Include="Autofac" Version="8.2.0" />
     <PackageVersion Include="AWSSDK.CloudWatch" Version="3.7.402.63" />
-    <PackageVersion Include="AWSSDK.SecurityToken" Version="3.7.401.78" />
+    <PackageVersion Include="AWSSDK.SecurityToken" Version="4.0.0" />
     <PackageVersion Include="Azure.Identity" Version="1.13.2" />
     <PackageVersion Include="Azure.Monitor.Query" Version="1.6.0" />
     <PackageVersion Include="Azure.ResourceManager.ServiceBus" Version="1.1.0" />