[llvm] [GitHub][CI] Add a new container to use for the abi tests (PR #166886)

[Aiden Grossman via llvm-commits]

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@@ -72,6 +72,8 @@ jobs:
     if: github.repository_owner == 'llvm'
     needs: abi-dump-setup
     runs-on: ubuntu-24.04
+    container:
+      image: ${{ format('ghcr.io/{0}/ci-container-abi-tests',github.repository_owner) }}
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boomanaiden154 wrote:

I think I would prefer it that way. We don't support using it elsewhere, so this just adds (a small amount of) complexity for no real benefit from what I can see.

https://github.com/llvm/llvm-project/pull/166886