[llvm] workflows: Add a new job for packaging release sources (PR #91834)

[Tom Stellard via llvm-commits]

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@@ -0,0 +1,59 @@
+name: Release Sources
+
+permissions:
+  contents: read
+
+on:
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tstellar wrote:

I added a pull_request trigger.  Let me know what you think I had to disable the attestation step, because it doesn't have the right permissions when running from a fork.

https://github.com/llvm/llvm-project/pull/91834