Outdated certificates for nuget with mono 6.12.0.147

Just today when I tired to compile Godot 3.4.2 my builds with these containers started failing with this error:
```
/usr/lib/mono/msbuild/Current/bin/NuGet.targets(131,5): error : Failed to retrieve information about 'EnvDTE' from remote source 'https://api.nuget.org/v3-flatcontainer/envdte/index.json'. [/root/godot/modules/mono/editor/GodotTools/GodotTools.sln]
/usr/lib/mono/msbuild/Current/bin/NuGet.targets(131,5): error : The SSL connection could not be established, see inner exception. [/root/godot/modules/mono/editor/GodotTools/GodotTools.sln]
/usr/lib/mono/msbuild/Current/bin/NuGet.targets(131,5): error : Authentication failed, see inner exception. [/root/godot/modules/mono/editor/GodotTools/GodotTools.sln]
/usr/lib/mono/msbuild/Current/bin/NuGet.targets(131,5): error : Ssl error:1000007d:SSL routines:OPENSSL_internal:CERTIFICATE_VERIFY_FAILED [/root/godot/modules/mono/editor/GodotTools/GodotTools.sln]
/usr/lib/mono/msbuild/Current/bin/NuGet.targets(131,5): error : at /root/mono-6.12.0.147/external/boringssl/ssl/handshake_client.c:1132 [/root/godot/modules/mono/editor/GodotTools/GodotTools.sln]
```

I remember hearing that nuget announced that they would move to some new Microsoft root certs at some point. Maybe they did? Should these images be updated for example to use Fedora 35 or a newer mono version, would that help?

I already tried pulling in the newest fedora:34 base image and re-running `./build.sh 3.x mono-6.12.0.147` but when compiling Godot 3.4.2 with those freshly made images, it still fails.