fix: Address vulnerable dependencies

[rogerbarreto]

Motivation

Address current vulnerable dependent packages.

D:\repo\community\google-dotnet-genai\Google.GenAI [main ≡ +22 ~0 -0 !]> dotnet package list --vulnerable --include-transitive
Restore succeeded with 2 warning(s) in 0.5s
    D:\repo\community\google-dotnet-genai\Google.GenAI\Google.GenAI.csproj : warning NU1903: Package 'System.Text.Json' 8.0.0 has a known high severity vulnerability, https://github.com/advisories/GHSA-8g4q-xg66-9fp4
    D:\repo\community\google-dotnet-genai\Google.GenAI\Google.GenAI.csproj : warning NU1903: Package 'System.Text.Json' 8.0.0 has a known high severity vulnerability, https://github.com/advisories/GHSA-hh2w-p6rv-4g7w

Build succeeded with 2 warning(s) in 0.6s

The following sources were used:
   https://api.nuget.org/v3/index.json
   C:\Program Files (x86)\Microsoft SDKs\NuGetPackages\

Project `Google.GenAI` has the following vulnerable packages
   [netstandard2.1]:
   Top-level Package       Requested   Resolved   Severity   Advisory URL
   > System.Text.Json      8.0.0       8.0.0      High       https://github.com/advisories/GHSA-hh2w-p6rv-4g7w
                                                  High       https://github.com/advisories/GHSA-8g4q-xg66-9fp4

   Transitive Package         Resolved   Severity   Advisory URL
   > System.Net.Security      4.3.0      Moderate   https://github.com/advisories/GHSA-ch6p-4jcm-h8vh
                                         High       https://github.com/advisories/GHSA-6xh7-4v2w-36q6
                                         High       https://github.com/advisories/GHSA-qhqf-ghgh-x2m4
                                         Moderate   https://github.com/advisories/GHSA-j8f4-2w4p-mhjc

   [net8.0]:
   Transitive Package         Resolved   Severity   Advisory URL
   > System.Net.Security      4.3.0      Moderate   https://github.com/advisories/GHSA-ch6p-4jcm-h8vh
                                         High       https://github.com/advisories/GHSA-6xh7-4v2w-36q6
                                         High       https://github.com/advisories/GHSA-qhqf-ghgh-x2m4
                                         Moderate   https://github.com/advisories/GHSA-j8f4-2w4p-mhjc

[rogerbarreto]

Closing this PR as this was addressed by the merged one.

• feat: Add Support for .Net Standard 2.0 #90