Fix cross-compile protoc and increase build timeout

- Add Cross.toml: installs protobuf-compiler inside the cross Docker
  containers used for Linux ARM64 builds (substrait/prost-build requires
  protoc at compile time, and the cross images don't include it)
- Increase build-cli timeout from 15 → 45 minutes: adding substrait +
  DataFusion to the workspace significantly increases compile time on
  Windows and macOS ARM64 runners

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

Author: edmondop

.github/workflows/build-cli.yml

@@ -26,7 +26,7 @@ on:
 jobs:
   build-cli:
     name: Build compiler
-    timeout-minutes: 15
+    timeout-minutes: 45
     runs-on: ${{ inputs.os }}
     steps:
       - uses: actions/checkout@v2

Cross.toml

@@ -0,0 +1,10 @@
+# Cross.toml — configuration for cross-compilation via the `cross` tool.
+# The `pre-build` commands run inside the cross Docker container before cargo build.
+# This is needed because `substrait` (via prost-build) requires `protoc` at compile time,
+# but the cross Docker images don't include it by default.
+
+[target.aarch64-unknown-linux-musl]
+pre-build = ["apt-get update && apt-get install -y protobuf-compiler"]
+
+[target.aarch64-unknown-linux-gnu]
+pre-build = ["apt-get update && apt-get install -y protobuf-compiler"]