Enable tests on ucm trunk builds again

Now that unisonweb/unison#5744 is merged.

Author: ceedubs

.github/workflows/cloud-client-tests.yml

@@ -21,8 +21,7 @@ jobs:
         ucm-release-version:
           - 'release%2F0.5.25'
           - 'release%2F0.5.41'
-          # Temporarily disabling until a regression is addressed.
-          #- 'trunk-build'
+          - 'trunk-build'
     steps:
       - name: Check out repository code
         uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2