Remove coverage checks for nightly for now and enable manula dispatch

Author: markurtz

.github/workflows/nightly.yml

@@ -3,6 +3,7 @@ name: Nightly
 on:
   schedule:
     - cron: '0 0 * * *'  # Runs at midnight every night
+  workflow_dispatch:  # Enables manual triggering of the workflow
 
 jobs:
   link-checks:
@@ -35,7 +36,7 @@ jobs:
       - name: Install dependencies
         run: pip install tox
       - name: Run unit tests
-        run: tox -e test-unit -- --cov=guidellm --cov-report=term-missing --cov-fail-under=75
+        run: tox -e test-unit
 
   integration-tests:
     runs-on: ubuntu-latest