Update GitHub Actions workflow

Signed-off-by: Sora Morimoto <[email protected]>

.github/dependabot.yml

@@ -0,0 +1,6 @@
+version: 2
+updates:
+  - package-ecosystem: github-actions
+    directory: /
+    schedule:
+      interval: weekly

.github/workflows/master.yml

@@ -1,37 +1,29 @@
 name: Main workflow
 
 on:
-  pull_request:
   push:
+  pull_request:
   schedule:
-    - cron: "0 13 * * 1" # Every Monday at 1PM UTC
-    # https://jasonet.co/posts/scheduled-actions/
+    # Prime the caches every Monday
+    - cron: 0 1 * * MON
 
 jobs:
   build:
-    strategy:
-      fail-fast: false
-      matrix:
-        os:
-          - ubuntu-latest
-        ocaml-compiler:
-          - 4.13.x
-
-    runs-on: ${{ matrix.os }}
+    runs-on: ubuntu-latest
 
     steps:
-      - name: Checkout code
-        uses: actions/checkout@v2
+      - name: Checkout tree
+        uses: actions/checkout@v4
 
-      - name: Use OCaml ${{ matrix.ocaml-compiler }}
+      - name: Set-up OCaml
         uses: ocaml/setup-ocaml@v2
         with:
-          ocaml-compiler: ${{ matrix.ocaml-compiler }}
+          ocaml-compiler: "4.14"
+          allow-prerelease-opam: true
 
       # ideally it should be done by `opam install . --deps-only` but right now
       # we have opam 1.x in the repo, and I'm not very optimistic to even try it
-      - run: opam depext conf-dbm -y
-      - run: opam install eliom ocsigen-toolkit cairo2 ocsipersist-dbm calendar syndic -y
+      - run: opam install eliom ocsigen-toolkit cairo2 ocsipersist-dbm calendar syndic
 
       - name: Compiling simple
         run: opam exec -- make -C simple all