fix: Testing highlightjs-cairo v4.0 in starknet-docs-antora-ui (stark…

…net-io#1153)

* Testing highlightjs-cairo v4.0 in starknet-docs-antora-ui

* Changed AsciiDoc source language from Rust to Cairo in contract-abi.adoc

* Changed default tab for Contract ABI example to Cairo v2 instead of v1.

* Reverted playbook.yml to use the ui-bundle.zip on the HEAD branch from the starknet-docs-antora-ui repo.

* Changed one last instance of `[source,rust]` to `[source,cairo]`