ci: Fix upterm action version from v3 to v1

The v3 version does not exist, causing CI failures. The correct version
is v1 as documented in the action's README.

Assisted-by: Claude Code (Sonnet 4.5)

Author: cgwalters

.github/workflows/ci.yml

@@ -139,7 +139,7 @@ jobs:
           libvirt: true
 
       - name: Setup upterm session for debugging
-        uses: owenthereal/action-upterm@v3
+        uses: owenthereal/action-upterm@v1
         with:
           limit-access-to-actor: false
           limit-access-to-users: cgwalters