[llvm] [infra] Add git to Linux container (PR #82687)

[Natalie Chouinard via llvm-commits]

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@@ -1,3 +1,5 @@
+; DONOTSUBMIT: Temp change to make SPIR-V Tests run on the PR.
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sudonatalie wrote:

I see, removed it. For SPIR-V tests it's fine to test it live but I'm not sure what to do about the stage2 bot.

https://github.com/llvm/llvm-project/pull/82687