[llvm] [RISCV] Loosen the requirement of shadow stack codegen to Zimop (PR #152251)

[Jesse Huang via llvm-commits]

jaidTw wrote:

> @jaidTw Looks like you've got a CI failure. Could you take a look at it?

```
2025-08-28T02:43:44.1309989Z Running runtimes checks requiring reconfiguring targets: check-cxx check-cxxabi check-unwind
2025-08-28T02:43:44.1325123Z sccache: Starting the server...
2025-08-28T02:43:44.1402784Z sccache: error: Cannot open/write log file 'artifacts/sccache.log'
2025-08-28T02:43:54.1426567Z sccache: error: Timed out waiting for server startup
2025-08-28T02:43:54.1460511Z ##[error]Process completed with exit code 2.
```
Re-running to see if we can get it fixed

https://github.com/llvm/llvm-project/pull/152251