ci: bump GitHub Actions to v5 for Node 24 compatibility

actions/checkout, actions/cache, actions/upload-artifact, and
actions/download-artifact bumped from v4 to v5 across both
ci.yml and release.yml. Pre-empts the 2026-06-02 Node 20
deprecation deadline.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.github/workflows/release.yml

@@ -32,7 +32,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
 
       - name: Install Rust stable
         uses: dtolnay/rust-toolchain@stable
@@ -44,7 +44,7 @@ jobs:
             libasound2-dev libudev-dev libwayland-dev libxkbcommon-dev
 
       - name: Cache cargo registry + build artifacts
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: |
             ~/.cargo/registry
@@ -63,7 +63,7 @@ jobs:
           cp -r assets solitaire-quest/
           tar -czf solitaire-quest-linux-x86_64.tar.gz solitaire-quest
 
-      - uses: actions/upload-artifact@v4
+      - uses: actions/upload-artifact@v5
         with:
           name: linux
           path: solitaire-quest-linux-x86_64.tar.gz
@@ -76,7 +76,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
 
       - name: Install Rust stable + Android targets
         uses: dtolnay/rust-toolchain@stable
@@ -90,7 +90,7 @@ jobs:
         run: echo "ANDROID_NDK_ROOT=$ANDROID_NDK_LATEST_HOME" >> $GITHUB_ENV
 
       - name: Cache cargo registry + cargo-apk binary + build artifacts
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: |
             ~/.cargo/registry
@@ -134,7 +134,7 @@ jobs:
              "solitaire-quest-${{ github.ref_name }}.apk"
           rm release.keystore
 
-      - uses: actions/upload-artifact@v4
+      - uses: actions/upload-artifact@v5
         with:
           name: android
           path: solitaire-quest-${{ github.ref_name }}.apk
@@ -148,11 +148,11 @@ jobs:
     needs: [build-linux, build-android]
 
     steps:
-      - uses: actions/download-artifact@v4
+      - uses: actions/download-artifact@v5
         with:
           name: linux
 
-      - uses: actions/download-artifact@v4
+      - uses: actions/download-artifact@v5
         with:
           name: android