Bump System.Text.Json from 4.7.2 to 5.0.0 in /src

Bumps [System.Text.Json](https://github.com/dotnet/runtime) from 4.7.2 to 5.0.0.
- [Release notes](https://github.com/dotnet/runtime/releases)
- [Commits](https://github.com/dotnet/runtime/commits)

Signed-off-by: dependabot[bot] <support@github.com>

src/aggregator-function/aggregator-function.csproj

@@ -32,7 +32,7 @@
   </ItemGroup>
   <ItemGroup>
     <!-- resolves MSB3277 -->
-    <PackageReference Include="System.Text.Json" Version="4.7.2" />
+    <PackageReference Include="System.Text.Json" Version="5.0.0" />
     <PackageReference Include="Microsoft.AspNetCore.Mvc.WebApiCompatShim" Version="2.2.0" />
     <PackageReference Include="Microsoft.Azure.WebJobs" Version="3.0.18" />
     <PackageReference Include="Microsoft.Extensions.Configuration.EnvironmentVariables" Version="3.1.8" />

src/aggregator-host/aggregator-host.csproj

@@ -21,7 +21,7 @@
 
   <ItemGroup>
     <!-- resolves MSB3277 -->
-    <PackageReference Include="System.Text.Json" Version="4.7.2" />
+    <PackageReference Include="System.Text.Json" Version="5.0.0" />
     <PackageReference Include="Microsoft.Extensions.Hosting" Version="3.1.8" />
   </ItemGroup>
 

src/unittests-function/unittests-function.csproj

@@ -22,7 +22,7 @@
 
   <ItemGroup>
     <!-- resolves MSB3277 -->
-    <PackageReference Include="System.Text.Json" Version="4.7.2" />
+    <PackageReference Include="System.Text.Json" Version="5.0.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.7.1" />
     <PackageReference Include="Microsoft.AspNetCore.Mvc" Version="2.2.0" />
     <PackageReference Include="NSubstitute" Version="4.2.2" />