CI: allow manual workflow dispatches to run

Allow running the nightly tests on manual workflow dispatches regardless
of the repository. This allows us to start the job on forks that have
the correct runner scale set deployed.

Signed-off-by: Dennis Maisenbacher <[email protected]>

Author: MaisenbacherD

.github/workflows/run-nightly-tests.yml

@@ -8,7 +8,7 @@ on:
 
 jobs:
   nightly-tests:
-    if: github.repository == 'linux-nvme/nvme-cli'
+    if: ${{ github.event_name == 'workflow_dispatch' || github.repository == 'linux-nvme/nvme-cli' }}
     runs-on: arc-vm-nvme-cli
     steps:
       - uses: actions/checkout@v5