Ensure v14.0.0 starts at beta1

Directory.Build.props

@@ -43,7 +43,7 @@
     <PackageOutputPath>$(BaseArtifactsPath)pkg/$(Configuration)/</PackageOutputPath>
     <Product>LLVMSharp</Product>
     <VersionPrefix>14.0.0</VersionPrefix>
-    <VersionSuffix Condition="'$(EXCLUDE_SUFFIX_FROM_VERSION)' != 'true'">beta2</VersionSuffix>
+    <VersionSuffix Condition="'$(EXCLUDE_SUFFIX_FROM_VERSION)' != 'true'">beta1</VersionSuffix>
     <VersionSuffix Condition="'$(GITHUB_EVENT_NAME)' == 'pull_request'">pr</VersionSuffix>
   </PropertyGroup>