fix the action script

Author: Gurpreet Singh

.github/workflows/build.yml

@@ -38,7 +38,7 @@ jobs:
           buildNumber="${{steps.gitversion.outputs.preReleaseNumber}}${{ steps.gitversion.outputs.buildMetaData }}"
           
           if [[ "${GITHUB_REF}" != "refs/heads/${{ github.event.repository.default_branch }}" ]]; then
-            buildNumber = "${buildNumber}-beta"
+            buildNumber="${buildNumber}-beta"
           fi
           
           packageVersion="${{ steps.gitversion.outputs.majorMinorPatch }}.${buildNumber}"