CI: bump checkout v4->v5 and setup-typst v4->v5 (Node 24)

Both actions ran on the deprecated Node.js 20 (forced off after 2026-06-16).
- actions/checkout@v5: Node 24 only; no input changes (we use it with none).
- typst-community/setup-typst@v5: Node 24; drops the unused `local-packages`
  input and action outputs, neither of which we use.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: isPANN

.github/workflows/ci.yml

@@ -31,7 +31,7 @@ jobs:
     name: Rustfmt
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: dtolnay/rust-toolchain@stable
         with:
           components: rustfmt
@@ -43,7 +43,7 @@ jobs:
     name: Clippy
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: dtolnay/rust-toolchain@stable
         with:
           components: clippy
@@ -60,14 +60,14 @@ jobs:
     env:
       FEATURES: "ilp-highs example-db"
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: dtolnay/rust-toolchain@stable
       - uses: taiki-e/install-action@v2
         with:
           tool: nextest
       - uses: Swatinem/rust-cache@v2
       - name: Install typst
-        uses: typst-community/setup-typst@v4
+        uses: typst-community/setup-typst@v5
 
       - name: Compile tests
         run: cargo nextest run --no-run --workspace --features "$FEATURES"
@@ -96,7 +96,7 @@ jobs:
     name: Code Coverage
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: dtolnay/rust-toolchain@stable
         with:
           components: llvm-tools-preview