[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'm going to try to merge this tomorrow, so I can use it out for the upcoming 18.1.8 release.  The pull_request trigger does seem useful even if it is somewhat invasive.

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