docs: update SSH command format to use suffix (#18085)

Refactor the workspace SSH command syntax across the project to use the
"workspace.coder" format instead of "coder.workspace". This standardizes
the SSH host entries for better consistency and clarity.

This is a follow-up from #17445 and recommends using the suffix-based
format for all new Coder versions.

<img width="418" alt="image"
src="https://github.com/user-attachments/assets/3893f840-9ce1-4803-a013-736068feb328"
/>

docs/tutorials/testing-templates.md

@@ -103,9 +103,8 @@ jobs:
       - name: Create a test workspace and run some example commands
         run: |
           coder create -t $TEMPLATE_NAME --template-version ${{ steps.name.outputs.version_name }} test-${{ steps.name.outputs.version_name }} --yes
-          coder config-ssh --yes
           # run some example commands
-          ssh coder.test-${{ steps.name.outputs.version_name }} -- make build
+          coder ssh test-${{ steps.name.outputs.version_name }} -- make build
 
       - name: Delete the test workspace
         if: always()