Update release-package.yml (#25)

Author: VisualBean

.github/workflows/release-package.yml

@@ -30,7 +30,7 @@ jobs:
 
       - name: Get last char shortened GITHUB_RUN_ID
         id: slug
-        run: echo "::set-output name=RUNID::$(echo ${$GITHUB_RUN_ID} | cut -c1-9)"
+        run: echo "::set-output name=RUNID::$(echo ${GITHUB_RUN_ID} | cut -c1-9)"
 
       - name: Build ${{ matrix.package-name }} project and pack NuGet package
         run: dotnet pack src/${{ matrix.package-name }}/${{ matrix.package-name }}.csproj -c Release -o out-${{ matrix.package-name }} -p:PackageVersion=0.1.${{ steps.slug.outputs.RUNID }}.$GITHUB_RUN_NUMBER-prerelease