[CI] [ArchLinux] Update keys

To avoid "Signature is unknown trust"

.github/workflows/coq-archlinux.yml

@@ -25,6 +25,7 @@ jobs:
     steps:
     - name: Install system dependencies
       run: |
+        pacman-key --refresh-keys
         pacman --noconfirm -Syu base-devel git make python3 which jq ghc ghc-static time diffutils coq ocaml-zarith --needed
     - uses: actions/checkout@v4
       with: