ci: add libclang-dev for tree-sitter cargo build

tree-sitter-cli depends on rquickjs-sys which uses bindgen, requiring
libclang. Add libclang-dev to both the CI rustup step and the script's
cargo fallback path so it works in real codespaces too.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: tarebyte

.github/workflows/ci.yml

@@ -89,7 +89,7 @@ jobs:
       - name: Install Rust toolchain (old glibc only)
         if: matrix.image == 'ubuntu:20.04'
         run: |
-          apt-get install -y build-essential
+          apt-get install -y build-essential libclang-dev
           curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs \
             | sh -s -- -y --profile minimal
           echo "$HOME/.cargo/bin" >> "$GITHUB_PATH"

script/install-codespace-tools

@@ -95,6 +95,10 @@ else
     GLIBC_VER=$(getconf GNU_LIBC_VERSION 2>/dev/null | awk '{print $2}' || echo "unknown")
     echo "  Installing tree-sitter-cli via cargo (glibc ${GLIBC_VER} < 2.35)..."
     if command -v cargo >/dev/null 2>&1; then
+      if ! dpkg -s libclang-dev >/dev/null 2>&1; then
+        echo "    sudo: installing libclang-dev (needed by bindgen)..."
+        sudo apt-get install -yq libclang-dev >/dev/null 2>&1
+      fi
       cargo install tree-sitter-cli --root "$HOME/.local"
       echo "  ✓ tree-sitter installed ($(tool_version tree-sitter), $((SECONDS - start))s)"
     else