ci: update apt repositories on every run

This is needed because the github images are out-of-date and the
dependencies' fetching fails otherwise

Signed-off-by: Pau Ruiz Safont <pau.ruizsafont@cloud.com>

Author: psafont

.github/workflows/0.150-lcm.yml

@@ -48,6 +48,9 @@ jobs:
           # invalidate cache daily, gets built daily using a scheduled job
           key: ${{ steps.cache-key.outputs.date }}-0.150
 
+      - name: Update Ubuntu repositories
+        run: sudo apt-get update
+
       - name: Use ocaml
         uses: avsm/setup-ocaml@v1
         with: