Update checkout version and release string

.github/workflows/main_matrix.yml

@@ -426,7 +426,7 @@ jobs:
     needs: [gather-artifacts, after-checks]
     steps:
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
           
       - name: Setup Python
         uses: actions/setup-python@v4
@@ -468,7 +468,7 @@ jobs:
         with:
           draft: true
           prerelease: true
-          release_name: Meshtastic Device ${{ steps.version.outputs.version }} alpha - Public Preview
+          release_name: Meshtastic Device ${{ steps.version.outputs.version }} Alpha
           tag_name: v${{ steps.version.outputs.version }}
           body: |
             Autogenerated by github action, developer should edit as required before publishing...