Update to use v4 of the Tailscale GitHub Action

Author: armstrongl

.github/workflows/test.yml

@@ -21,7 +21,7 @@ jobs:
         go-version: '1.23'
 
     - name: Connect to Tailscale
-      uses: tailscale/github-action@v3
+      uses: tailscale/github-action@v4
       with:
         oauth-client-id: ${{ secrets.TS_OAUTH_CLIENT_ID }}
         oauth-secret: ${{ secrets.TS_OAUTH_SECRET }}