ci: build wasm binary during docs deployment

[Mossaka]

Summary

• Adds Go setup and WebAssembly compiler build step to the docs deployment workflow, running scripts/bundle-wasm-docs.sh before the Astro build
• Expands path triggers to include cmd/gh-aw-wasm/**, pkg/**, and scripts/bundle-wasm-docs.sh so Go changes affecting the wasm build trigger a docs rebuild

Test plan

• Verify docs workflow triggers on PRs touching cmd/gh-aw-wasm/, pkg/, or scripts/bundle-wasm-docs.sh
• Verify Go is set up correctly and bundle-wasm-docs.sh runs before the Astro build
• Verify the docs build still succeeds end-to-end

🤖 Generated with Claude Code

[Copilot]

Pull request overview

This PR enables the docs deployment workflow to build the WebAssembly compiler binary, ensuring the interactive playground in the documentation always uses the latest compiler code. The workflow now sets up Go and runs the wasm bundling script before building the Astro documentation site.

Changes:

• Added path triggers to rebuild docs when Go source code affecting the wasm build changes (cmd/gh-aw-wasm/**, pkg/**, scripts/bundle-wasm-docs.sh)
• Added Go setup and wasm build steps to the docs build job, running before the Astro build

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