chore: enable deterministic builds on appveyor

Author: hazzik

.gitignore

@@ -160,6 +160,7 @@ PublishScripts/
 
 # NuGet Packages
 *.nupkg
+*.snupkg
 # The packages folder can be ignored because of Package Restore
 **/packages/*
 # except build/, which is used as an MSBuild target.

appveyor.yml

@@ -3,7 +3,7 @@ image: Visual Studio 2019
 environment:
   IGNORE_NORMALISATION_GIT_HEAD_MOVE: 1
 build_script:
-  - dotnet pack -c Release -o out
+  - dotnet pack -c Release -o out -p:ContinuousIntegrationBuild=true 
 artifacts:
   - path: out\*.*nupkg
 deploy: