[llvm] [Github][CI] Name Premerge Jobs Experimental (PR #128227)

[Aiden Grossman via llvm-commits]

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@@ -25,6 +25,7 @@ concurrency:
 
 jobs:
   premerge-checks-linux:
+    name: Linux Premerge Checks (Experimental)
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boomanaiden154 wrote:

Thanks. Applied.

https://github.com/llvm/llvm-project/pull/128227