Flaky test: Various arcane stack problems in buildkite (pantry, libffi, ...)

[Anviking]

Please ensure:

• This is actually a flaky test already present in the code and not caused by your PR.

Context

In the past we've sometime had to clear the stack caches due to weird and arcane problems.

Job name

Buildkite

Test case name(s)

No response

Error message

Currently at least two. Mostly:

Encountered error while migrating Pantry database:
--
  | SQLite3 returned ErrorNotFound while attempting to perform prepare "SELECT sql FROM sqlite_master WHERE type='table' AND name=?": database disk image is malformed
  | Please report this on https://github.com/commercialhaskell/stack/issues
  | As a workaround you may delete Pantry database in /build/cardano-wallet.stack/pantry/pantry.sqlite3 triggering its recreation.
  | error: Command exited with code 1!

But also one instance of:

cardano-wallet-core-integration> /var/lib/buildkite-agent-iohk/.stack/setup-exe-cache/x86_64-linux-nix/Cabal-simple_mPHDZzAJ_3.2.1.0_ghc-8.10.7: error while loading shared libraries: libffi.so.7: cannot open shared object file: No such file or directory

Build link

https://buildkite.com/input-output-hk/cardano-wallet/builds/18402

[Anviking]

Ain't got no stack no more.

...now we have cabal cache issues instead 😃