[llvm] workflows: Rewrite build-ci-container to work on larger runners (PR #117353)

[Aiden Grossman via llvm-commits]

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@@ -19,13 +19,11 @@ RUN curl -O -L https://github.com/llvm/llvm-project/archive/refs/tags/llvmorg-$L
 
 WORKDIR /llvm-project-llvmorg-$LLVM_VERSION
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boomanaiden154 wrote:

Can we rename this file to something other than `stage1` now that we only have a single stage?

https://github.com/llvm/llvm-project/pull/117353