Add Linux build job to CI and include Linux artifacts in release

[aa2013]

Motivation

• Provide prebuilt Linux artifacts alongside existing Android builds for both x86_64 and arm64 architectures.
• Ensure liblua and lua-cjson binaries are built and published in the same release as the Android artifacts.

Description

• Added a new build-linux job to .github/workflows/build-android-lua.yml that builds for x86_64 and arm64 using a simple cross-toolchain and produces liblua and cjson shared objects.
• Added caching and conditional download steps for Lua source (lua-${{ env.LUA_VERSION }}) and lua-cjson source, and an Install Linux build dependencies step that installs required packages.
• Implemented toolchain selection using the job matrix, built liblua.so and cjson.so with -fPIC and copied outputs to output/linux/${{ matrix.architecture }} and uploaded artifacts with actions/upload-artifact@v4.
• Updated the create-release job to depend on build-linux, broadened the artifact download pattern to lua-*-*, and updated the release name, tag_name, and files list to include the new Linux artifacts.

Testing

• No automated tests were executed as part of this changeset; the additions are workflow changes that will be validated when the GitHub Actions workflow is run and will produce build artifacts on execution.

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Codex Task