`cabal-testsuite/PackageTests/NewBuild/CmdRun/Terminate/cabal.test.hs` is flaky

[hasufell]

Example failures:

• https://github.com/haskell/cabal/actions/runs/16434730153/job/46442694152#step:8:7468
• https://github.com/haskell/cabal/actions/runs/16434730153/job/46442854971#step:8:2054

Re-running usually fixes it.

[ulysses4ever]

dup of #8416