Update GitHub Actions workflows. (#29)

This PR was automatically generated by the
update-native-provider-workflows workflow in the pulumi/ci-mgmt repo,
from commit 5abcb86d6b26ccd5910ffe8ad512bca68eaa07b3.

.github/workflows/prerelease.yml

@@ -7,7 +7,7 @@ on:
     - v*.*.*-**
 env:
   GITHUB_TOKEN: ${{ secrets.PULUMI_BOT_TOKEN }}
-  PROVIDER: dockerbuild
+  PROVIDER: docker-build
   PULUMI_ACCESS_TOKEN: ${{ secrets.PULUMI_ACCESS_TOKEN }}
   PULUMI_LOCAL_NUGET: ${{ github.workspace }}/nuget
   NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
@@ -24,7 +24,7 @@ env:
   SIGNING_KEY: ${{ secrets.JAVA_SIGNING_KEY }}
   SIGNING_PASSWORD: ${{ secrets.JAVA_SIGNING_PASSWORD }}
   GOVERSION: 1.21.x
-  NODEVERSION: 16.x
+  NODEVERSION: 20.x
   PYTHONVERSION: "3.11"
   DOTNETVERSION: |
     6.0.x