Update dotnet-core-release.yml

releasing beta build

Author: kccarter76

.github/workflows/dotnet-core-release.yml

@@ -11,7 +11,7 @@ jobs:
   build:
     runs-on: ${{ matrix.os }}
     env:
-      VERSION: 4.2.0-alpha.1
+      VERSION: 4.2.0-beta.1
     strategy:
       matrix:
         os: [ubuntu-latest]