tool.drcacheoff.warmup-pthreads-windows-split failed with "Failed to map encoding file"

This happened on a master merge on [aarch64-sve-precommit-128](https://github.com/DynamoRIO/dynamorio/actions/runs/23872374313/job/69607340104#logs):
```
2026-04-01T21:53:35.1682277Z 308: CMake Error at /opt/actions-runner/_work/dynamorio/dynamorio/suite/tests/process_cmdline.cmake:109 (message):
2026-04-01T21:53:35.1682950Z 308: *** postcmd failed (1): ERROR: failed to initialize analyzer: raw2trace
2026-04-01T21:53:35.1683433Z 308: failed: Failed to parse module fileFailed to map encoding file
2026-04-01T21:53:35.1683773Z 308:
2026-04-01T21:53:35.1683918Z 308: ***
2026-04-01T21:53:35.1684071Z 308:
2026-04-01T21:53:35.1684248Z 308: Call Stack (most recent call first):
2026-04-01T21:53:35.1684732Z 308: /opt/actions-runner/_work/dynamorio/dynamorio/suite/tests/runmulti.cmake:60 (process_cmdline)
2026-04-01T21:53:35.1685208Z 308:
2026-04-01T21:53:35.1685359Z 308:
2026-04-01T21:53:35.1685767Z 71/131 Test #308: code_api|tool.drcacheoff.warmup-pthreads-windows-split ...........***Failed 0.44 sec
```