build: I think CI can cross-build ios.

.gitea/workflows/build.yaml

@@ -7,9 +7,10 @@ jobs:
     runs-on: ubuntu-latest
     container:
       image: node:23-bookworm-slim
-      valid_volumes: ['/opt/keys']
+      valid_volumes: ['/opt/keys', '/opt/deps']
       volumes:
         - /opt/keys:/opt/keys
+        - /opt/deps:/opt/deps
     steps:
       - run: apt update && apt install -y doxygen git graphviz mingw-w64 libgpgme11 gcc-aarch64-linux-gnu zip unzip build-essential docker.io curl
       - name: check out code
@@ -17,6 +18,7 @@ jobs:
         with:
           submodules: true
       - run: ln -s /opt/keys .keys
+      - run: ln -s /opt/deps/ios_toolchain deps/ios_toolchain
       - name: Setup JDK
         uses: actions/setup-java@v3
         with: