Update standalone.md (#3819)

Author: philip-reed

docs/fundamentals/dashboard/standalone.md

@@ -25,7 +25,7 @@ docker run --rm -it -d \
     -p 18888:18888 \
     -p 4317:18889 \
     --name aspire-dashboard \
-    mcr.microsoft.com/dotnet/aspire-dashboard:9.0
+    mcr.microsoft.com/dotnet/aspire-dashboard:latest
 ```
 
 ## [PowerShell](#tab/powershell)
@@ -35,7 +35,7 @@ docker run --rm -it -d `
     -p 18888:18888 `
     -p 4317:18889 `
     --name aspire-dashboard `
-    mcr.microsoft.com/dotnet/aspire-dashboard:9.0
+    mcr.microsoft.com/dotnet/aspire-dashboard:latest
 ```
 
 ---