Skip building on tags for the ix/rx specific configs as a different config covers those already

appveyor.ix.yml

@@ -8,6 +8,8 @@ environment:
 
 skip_branch_with_pr: true
 
+skip_tags: true
+
 skip_commits:
   files:
     - '**/*.md'

appveyor.rx.yml

@@ -13,6 +13,8 @@ only_commits:
     - Rx.NET/**/*
     - '*'
 
+skip_tags: true
+
 skip_commits:
   files:
     - '**/*.md'